You'd be fine with an E30. I've been thinking about doing the same thing.
They're fairly easy cars to work on... parts are readily available and won't cost you an arm and a leg. You just have to search around on other enthusiast forums and craigslist. You'll find what you need--- theres a huge following for e30s.
I can't speak for specific problems since I haven't owned one or seriously looked into it too much but I'm sure some of the other guys on these boards will chime in.
1998 M3 Vert
1995 M3 Track Car
2008 335i - Retired