well when u go stat battling... the mk4 1.8t engine isnt that great in standard form.
150bhp or 180bhp isnt masses, and with your 16v len running at about 175, with the difference in weight, it should be able to do a 25th anniversary mk4!
IMHO... for a mk3 youd be best off with a rebuilt vr6 engine, decent exhaust system, induction kit, and some map fettling could see the naughty side of 200bhp, which is ample for daily road use!!!