dont wanna sound like im putting a downer on the engine conversion idea but why not do a 20vt instead of a valver lump. the reason i say this is if you get the right engine code its 180 BHP and also VW make a mk3 16v gti but not a 20vt if u get what i mean. why spend excess cash on a conversion that you could go and buy off the shelf.
(just a bit of food for thought there) anyways best of luck fella