Found in:
Incantatrix -> 3.5, Magic of Faerun, pg 31; web search points to the 3.0 version being int he 3.0 Magic of Faerun book, but I don't have that so can't confirm.
Initiate of the Sevenfold Veil -> 3.5, Complete Arcane, pg 44
I had recently looked at IofSFV myself for conversion but deemed it a bit too difficult for my own skills in converting to NWN. I felt the difficulty was in coding the warding, of course; some restrictions like 'can't force another creature into it' become difficult to implement in NWN, as well as 'creatures attacking thru the veil', since there are no tests for attacks that are made that miss the target. It might be possible to approximate these things, but the class seems like it would not convert smoothly and would be subject to many 'approximations'. That's purely my opinion of course!
Looking at the 3.5 Incantatrix, I'm not sure that an extra prohibited school is possible to do. Possibly its not possible on the front side (i.e. can't prevent taking the spells), but maybe on the back side the spells from the prohibited school can be made to auto-fail if cast by the Incantatrix.
With a brief look at the other abilities it seems like See / Strike Ethereal would have to be converted to something else.
I don't know how Instant Metamagic or Improved Metamagic would work - if the spell level incrementation is hard coded somewhere for the core NWN classes, I'd suspect that the ability would only be able to be made to work with the PRC Spellbook.
Not trying to be a downer, but those certainty look to be some tough classes to convert!
Yo,
ATalsen
