Having two arcane caster classes strikes me as bad design- they're two subclasses of an implied concept. This is my try at that parent concept.
Arcanist
BAB +1/2
Good save: Will
Class Skills: Bluff (Cha), Concentration (Con), Craft (Int), Decipher Script (Int), Knowledge (all skills, taken individually) (Int), Profession (Wis), and Spellcraft (Int).
Skill Points at 1st Level: (2 + Int modifier) x4.
Skill Points at Each Additional Level: 2 + Int modifier.
Spells/Day
(Level) 0/1/2/3/4/5/6/7/8/9
(1) 3/1
(2) 4/2
(3) 4/2/1
(4) 4/3/2
(5) 4/3/2/1
(6) 4/3/3/2
(7) 4/4/3/2/1
(8) 4/4/3/3/2
(9) 4/4/4/3/2/1
(10) 4/4/4/3/3/2
(11) 4/4/4/4/3/2/1
(12) 4/4/4/4/3/3/2
(13) 4/4/4/4/4/3/2/1
(14) 4/4/4/4/4/3/3/2
(15) 4/4/4/4/4/4/3/2/1
(16) 4/4/4/4/4/4/3/3/2
(17) 4/4/4/4/4/4/4/3/2/1
(18) 4/4/4/4/4/4/4/3/3/2
(19) 4/4/4/4/4/4/4/4/3/3
(20) 4/4/4/4/4/4/4/4/4/4
[The wizard spells/day chart.]
Spells Known
(Level) 0/1/2/3/4/5/6/7/8/9
(1) 4/2
(2) 5/2
(3) 5/3/0
(4) 6/3/1
(5) 6/4/2/0
(6) 7/4/2/1
(7) 7/5/3/2/0
(8) 8/5/4/2/1
(9) 8/5/4/3/2/0
(10) 9/5/4/3/2/1
(11) 9/5/5/4/3/2/0
(12) 9/5/5/4/3/2/1
(13) 9/5/5/4/4/3/2/0
(14) 9/5/5/4/4/3/2/1
(15) 9/5/5/4/4/4/3/2/0
(16) 9/5/5/4/4/4/3/2/1
(17) 9/5/5/4/4/4/3/3/2/0
(18) 9/5/5/4/4/4/3/3/2/1
(19) 9/5/5/4/4/4/3/3/3/2
(20) 9/5/5/4/4/4/3/3/3/3
[The sorceror spells-known chart, with a 0 tacked on to indicate no spells known of that level at appropriate levels. A 5th level arcanist can cast 3rd level spells, but doesn't know any yet.]
Spells: An arcanist casts spells from the sorceror/wizard list. An arcanist can either prepare her spells ahead of time, or cast them spontaneously.
Prepared spells are governed by Int, and have their DCs set by it. An arcanist can prepare bonus spells based on Int as well. She can prepare spells she knows, or from a spellbook.
Arcanists can spontaneously cast from the list of spells she knows. These spells are governed by Cha, and have their DCs set by it, and get bonus spells/day from it. Prepared spells reduce the number of spontaneous spells an arcanist can cast.
Example: A 1st level arcanist with an 16 int and 16 cha. Bonus spells/day for each are 1 1st-level spell. She can cast (ignoring bonus spells) 3 0th-level and 1 1st-level spell/day. She knows 4 0th- and 2 first-level spells.
She can cast spontaneously up to 4 1st level spells, which must be from the two she knows. She can prepare up to 4 1st level spells, from those she knows, or from a spellbook. Each prepared spell reduces the number of spontaneous spells castable per day. Prepare 2, and she can only cast 2 spontaneously.
So obviously, if you have a much higher Int, it's more optimal to just prepare all your spells; the known spells do ensure that if you lose access to a spellbook, you aren't completely hosed. If you have a much higher Charisma, you can prepare as many spells as you'd like, particularly ones you don't know but expect to use that day, and can still have a couple spontaneous slots with which to cast your known spells. Preparing spells is also useful for the higher-Cha caster who wants to use a metamagic feat and avoid the casting time extension for spontaneous metamagicked spells.
This class pretty much does away with the need for the Spell Mastery feat for wizards, and the Prepare Spell feat for sorcerors, those abilities are built-in.
What would be an appropriate bonus feat progression for this class? Obviously, they can get a familiar at 1st level. 1 every 5 like the wizard? Also, I don't think they should be able to convert prepared spells into a known spell spontaneously (like clerics), but that might be a new implementation for the Spell Mastery feat.
Spell Mastery:
Select a number of spells equal to your charisma bonus (int?) from the spells you know. They must be at least one level lower than the highest spell level you can cast. You can convert prepared spells of an equal or higher level into one of the spells you have mastered spontaneously, like a cleric casting cure spells.
Spellbooks: Act like a wizard in regards to this, I guess.
I am aware that this class is similar in concept to a class from AU, but that one has you prepare a number of spells every day, and then spontaneously cast those, right? This goes at it a slightly different way.
Arcanist
BAB +1/2
Good save: Will
Class Skills: Bluff (Cha), Concentration (Con), Craft (Int), Decipher Script (Int), Knowledge (all skills, taken individually) (Int), Profession (Wis), and Spellcraft (Int).
Skill Points at 1st Level: (2 + Int modifier) x4.
Skill Points at Each Additional Level: 2 + Int modifier.
Spells/Day
(Level) 0/1/2/3/4/5/6/7/8/9
(1) 3/1
(2) 4/2
(3) 4/2/1
(4) 4/3/2
(5) 4/3/2/1
(6) 4/3/3/2
(7) 4/4/3/2/1
(8) 4/4/3/3/2
(9) 4/4/4/3/2/1
(10) 4/4/4/3/3/2
(11) 4/4/4/4/3/2/1
(12) 4/4/4/4/3/3/2
(13) 4/4/4/4/4/3/2/1
(14) 4/4/4/4/4/3/3/2
(15) 4/4/4/4/4/4/3/2/1
(16) 4/4/4/4/4/4/3/3/2
(17) 4/4/4/4/4/4/4/3/2/1
(18) 4/4/4/4/4/4/4/3/3/2
(19) 4/4/4/4/4/4/4/4/3/3
(20) 4/4/4/4/4/4/4/4/4/4
[The wizard spells/day chart.]
Spells Known
(Level) 0/1/2/3/4/5/6/7/8/9
(1) 4/2
(2) 5/2
(3) 5/3/0
(4) 6/3/1
(5) 6/4/2/0
(6) 7/4/2/1
(7) 7/5/3/2/0
(8) 8/5/4/2/1
(9) 8/5/4/3/2/0
(10) 9/5/4/3/2/1
(11) 9/5/5/4/3/2/0
(12) 9/5/5/4/3/2/1
(13) 9/5/5/4/4/3/2/0
(14) 9/5/5/4/4/3/2/1
(15) 9/5/5/4/4/4/3/2/0
(16) 9/5/5/4/4/4/3/2/1
(17) 9/5/5/4/4/4/3/3/2/0
(18) 9/5/5/4/4/4/3/3/2/1
(19) 9/5/5/4/4/4/3/3/3/2
(20) 9/5/5/4/4/4/3/3/3/3
[The sorceror spells-known chart, with a 0 tacked on to indicate no spells known of that level at appropriate levels. A 5th level arcanist can cast 3rd level spells, but doesn't know any yet.]
Spells: An arcanist casts spells from the sorceror/wizard list. An arcanist can either prepare her spells ahead of time, or cast them spontaneously.
Prepared spells are governed by Int, and have their DCs set by it. An arcanist can prepare bonus spells based on Int as well. She can prepare spells she knows, or from a spellbook.
Arcanists can spontaneously cast from the list of spells she knows. These spells are governed by Cha, and have their DCs set by it, and get bonus spells/day from it. Prepared spells reduce the number of spontaneous spells an arcanist can cast.
Example: A 1st level arcanist with an 16 int and 16 cha. Bonus spells/day for each are 1 1st-level spell. She can cast (ignoring bonus spells) 3 0th-level and 1 1st-level spell/day. She knows 4 0th- and 2 first-level spells.
She can cast spontaneously up to 4 1st level spells, which must be from the two she knows. She can prepare up to 4 1st level spells, from those she knows, or from a spellbook. Each prepared spell reduces the number of spontaneous spells castable per day. Prepare 2, and she can only cast 2 spontaneously.
So obviously, if you have a much higher Int, it's more optimal to just prepare all your spells; the known spells do ensure that if you lose access to a spellbook, you aren't completely hosed. If you have a much higher Charisma, you can prepare as many spells as you'd like, particularly ones you don't know but expect to use that day, and can still have a couple spontaneous slots with which to cast your known spells. Preparing spells is also useful for the higher-Cha caster who wants to use a metamagic feat and avoid the casting time extension for spontaneous metamagicked spells.
This class pretty much does away with the need for the Spell Mastery feat for wizards, and the Prepare Spell feat for sorcerors, those abilities are built-in.
What would be an appropriate bonus feat progression for this class? Obviously, they can get a familiar at 1st level. 1 every 5 like the wizard? Also, I don't think they should be able to convert prepared spells into a known spell spontaneously (like clerics), but that might be a new implementation for the Spell Mastery feat.
Spell Mastery:
Select a number of spells equal to your charisma bonus (int?) from the spells you know. They must be at least one level lower than the highest spell level you can cast. You can convert prepared spells of an equal or higher level into one of the spells you have mastered spontaneously, like a cleric casting cure spells.
Spellbooks: Act like a wizard in regards to this, I guess.
I am aware that this class is similar in concept to a class from AU, but that one has you prepare a number of spells every day, and then spontaneously cast those, right? This goes at it a slightly different way.