Glad to see I have an admirer
For a four person party, there are plenty of options. You want to have thievery, but not to have it take up too much of your precious 120 levels, so I'd recomend my favorite thief1/ranger1/paladin2/mage drow build, since 20 DEX and INT can see you through the game. Get a fighter4(or paladin2)/morninglord of Lathander (possibly female drow) for a solid tank and bombardier. Your main tank should be an aasimir fighter4/paladin or a drow fighter/paladin 50/50, and the last one could be your choice. If you plan on only doing the normal game, I'd opt for another warrior, such as a shield dwarf fighter4/barbarian, or perhaps another paladin. If you plan on going on to HoF mode, then another spellcaster is in order; perhaps a drow sorcerer or a ranger1/paladin2/mage drow.
Why drow, you ask? The insane magic resistance is a godsend, and they have some of the highest stats of all subraces. the ECL penalty is overlookable, especially in a four person party.
A note on <6 parties, you may start getting less experience in fights. If this starts happening, the hold on to the levels of your solid tanks who don't benefit as much and lower your party average level. Not only will this net you normal xp, but you may even start getting an increase.
Good luck with IWD2!
