93 325i questions

I am in the market for one of these and I have a few questions. I read some stats about it and found on a site that the curb weight for the 4-door and the coupe are the same, is this actually true? Please give the weights if you have them. Also, I just wanted to know the simplest things I could put on this baby to make it faster. I was thinking of just doing the High Flow intake, some kind of good exhaust, and a performance chip. Can somebody please tell me the best company that makes each of these and approximately the price? Also, about some rims...would thjose 2002 m3 18" rims fit the 93 3-series? Thanks. Post pics if you want to.