Currently we've got the following classes, basic and alternate:
Holvir, paladin
Korin, ranger, alternate class: multiclass cleric/ranger
Nella, fighter, possible dual-class - cleric, druid, alternate class: multiclass fighter/cleric, multiclass fighter/druid
Severn, bard, alternate class: mage, multiclass fighter/mage
Teri, multiclass fighter/thief, alternate class: thief, multiclass mage/thief, multiclass fighter/mage/thief
But Baldur's Gate 2 engine offers more opportunities. So, when IWD NPC for IWD in BG2 engine is available, what new opportunities do you want? Make Teri a swashbuckler/assassin? Make Holvir an Undead Hunter? Make Nella a Kensai, Korin an archer, Severn a sorcerer?
My (current) list of ideas(I groan every time I think of them, alas):
Holvir, paladin, alternate class: undead hunter, inquisitor, cavalier
Korin, ranger, alternate class: multiclass cleric/ranger, stalker, beast master, archer
Nella, fighter, possible dual-class - cleric, druid, alternate class: multiclass fighter/cleric, multiclass fighter/druid, berserker, wizard slayer, kensai(for all kits - possible dual-class - cleric, druid), monk
Severn, bard, alternate class: mage, multiclass fighter/mage, wild mage, sorcerer, skald, jester, blade
Teri, multiclass fighter/thief, alternate class: thief, assassin, bounty hunter, swashbuckler, multiclass mage/thief, multiclass fighter/mage/thief
Mind that I'm not Nythrun, and constructing .cre files manually is very tedious(unfortunately!). So, please, offer other variants only if you'd like to play them(if you were playing IWD NPC via IWD-in-BG2).