I believe you need the 5 speed cars subframe, then about every other manual part. 5 speed is much easier since it came in some of the cars. HEC is a guy you might want to talk to he just did a 3500+5 speed swap with headers,etc so pretty much your plan. Heres his build thread if your curious.
http://www.grandamgt.com/forum/showt...ighlight=speed
I have a 3500 but Im auto and on stock tune so its not that much fun, on my tuned grand am the shifting is pretty fun.