Mithril Armor is almost a no-brainer.
Also, check out OA's Ashigaru Armor.
Build #1) Ftr 2-4 (Either Armored Mage Altnernative Class Feature or take Still Spell as your 1st level feat and whatever as your Ftr bonus feats and/or limit your PC to spells without somatic components- there is a list in the Dragon mag issue with the Modron on the cover)/Specialist Wizard X (Focused Specialist Alternative Class Feature- gives you so many spells/day, you're like a Sorcerer)/Eldritch Knight X
The Battle Caster feat from CompArc will let you use heavier armor & still cast spells.
Note- if you're not too concerned about feats, use one of the +0 Outsider races (like Neraphim PlnrHbk p12-13) and get proficiency with all Simple & Martial Weapons (MM), and simply bypass the Ftr levels while aiming at Eldritch Knight.
Build #1a) For the record, if you ever get to use Psionics, sub PsiWar for Fighter if you're only taking 2 levels of Ftr at first. For dropping from +2BAB to +1BAB, you gain access to Psionic Feats, leave the door open to Psionic Powers & PrCls, and get Expansion, the psionic version of Enlarge (but better because you can grow 2 sizes larger).
Build #2) Paladin 5+/KensaiX/Specialist Wizard 3+ (Focused Specialist Alternative Class Feature)
(A LG Soulborn from MoI can get you similar effects to Paladins).
If you're not concerned about Paladin spells (who is?), take the Holy Warrior Alternative Class Feature from CompChamp & gain some Feats.
Use any big 2 hd slashing weapon. Eventually, get it enchanted- don't worry about fancy enchantments- just boost its plusses. (If your game permits, there are all kinds of ways to boost it's base damage, too- racial abilities like Powerful Build; the feats Monkey Grip and Heavy Weapon; spells like Bull's Strength, Enlarge Person and Righteous Might, and the Psionic power Expansion)
Get to Kensai as soon as possible (Paladins and LG Soulborns are among the few classes that get there in 5), and boost your weapon's power. Personally, I usually keep adding powers that add d6's to its damage- Flame, Frost, Shock, Corrosive, Holy, etc. If your PC is a PA-Cleave-G.Cleaver, he'll be doing that all the time. On top of that, he'll be able to boost his Str by +8 for another +4/+4...stackable with all of the Str boosting spells and psionic abilities.
Learn the Whirling Blade spell- its an area spell mainly targeted upon your weapon, so it will be effective against critters with SR. It lets you throw your weapon and attack every target within a 60' line at your highest BAB, using either your Str or your casting stat (here, Int) for bonuses. (Its confusingly worded- its either an Area Effect spell or an Effect spell, so depending upon your DM's ruling, Sculpt Spell may work with it, further increasing its utility.) Unlike the Returning power, WB explicitly states that the weapon returns to the caster's hand after the spell expires.
Yeah...I know its a clunky way to do Lightning Bolt, but its cool... AND you can get crits with it!