Idrive330i and Terraphantm, i recommend go for the M3, I have just purchased a 97 Eurospec M3, it is awesome, I love it, the "M" badge and all that comes with it makes it an awesome experience every time I drive it! My advice is to get any car thoroughly checked by a qualified mechanic before buying, he should be able to identify through suspension and brake wear etc if it's been thrashed. If it does not have a documented service history (particularly for high mileage cars) walk away, these are high performance engines that need regular oil and coolant changes with top shelf products. Make sure the coolant is clean, if the coolant is clean but the bottle is dirty you will be asking for trouble.
It's only early days but the only issue with my car is the engine oil temp gauge is not working. The clutch was replaced and the Vanos was rebuilt at 150,000kms. It's a gem!
Be patient and wait for the right car (I searched for 8 months with plenty of lemons out there), the "M" experience is worth it.