An even better version of this is Dragonfire Adept, which has Draconic Knowledge, which grants +6 to all Knowledge skills and Spellcraft and lets you make checks as if trained. The class also has 4+Int skill points, all Knowledges as class skills, and a better skill list, other bonuses, and you can pick up Beguiling Influence at 3rd (no take 10 on UMD though).Hi,
All of the above suggestions are sound, but why are you only seeking to max out these skills; why not try to go above par.
Consider dipping into Warlock for two levels.
Onlt 2+ skill points per level, but
The Invokations you would want are
Otherwordly Whispers +6 profane bonus on Knowledge(Arcane), Knowledge(Religeon) and Knowledge(the Planes) [CMage p 124]
Beguiling Influence +6 profane bonus on Bluff, Diplomacy and Intimidate [CArc]
Thus you are netting 20+ skill points per level and are setting 6 of your skills at max+6
What else do you get for your experience pieces ?
1d6 Eldritch Blast, which is pretty inconsequential except perhaps as a vehicle for an occasion magic ranged touch sneak attack.
Oh and you also get Det magic at will.
The cost: you have to be Chaotic or Evil.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.