If and when ... where do I start?

Hey everybody. I am sort of new at this whole owning a bimmer thing, but I have been doing a lot of research about all of the models and performance upgrades. Mostly focusing on the 1990 525i (because thats what I currently have to work with). As I dig deeper and deeper into the subject I found out that there are more and more model and engine combos that I didn't know existed.

To get to the point. I would really like to buy a late model BMW that I could play with. I would really like to buy something mostly stock and start working on my race machine from there. My question is what would be the best base to start from? I really like the 5-series but it seems that almost everyone that really hops something up goes with the 3-series option. If anyone could give me a little advice or even point me toward a website that can lay these sort of fact out for me I would greatly appriciate it.

Thanks!

Hi, Camdog-
I doubt you'll get much response on this forum. Most of those here just want to keep their stock machines running. Those that want to hop up their cars usually go somewhere else, like roadfly.org
Good luck! I'm going to hop up what I can afford, namely my 1985 535i. Later models require deeper pockets.
Flunky