[Bozos of Bones]

I'd still try to avoid xp penalties, as a 4player party really hurts to be the level of a 6 player one.
So, a revamp I'd suggest:
1. Aasimar Fighter4/PaladinX. Paladins get really mean with dual longswords, Heretic's Bane and Fiendslayer. And if they have a high charisma, they're vortually unkillable.
2. Altho with an xp penalty and level adjustment of +3, this combination always worked wonders for me.
3. Drow Sorcerer, Staff-wielding. Wizards gain extra feats, but having two wizards in a party makes buying spells somewhat tedious.
4. I'd rather go with a Tiefling thief1/wizard2, light armors and dual short blades.