Get the 328is, they were made from 96 and latrer. I got a 95' 325is and I have been pretty happy with it after 7k. They are pretty reliable from what I have gathered from other owners. The 325 and the 328 have about the same HP, but the 328 has better bottom end torque due to the .3 extra liters of displacement. That is the only weakness I feel my car has. They can both break into high 14's w/ minor mods, so they are decently quick. I can run next to a mustang GT but it's not as fast as your trans am was. If you want a good site to check out, go to
www.bimmerforums.com I am HeLLroT325iS.