Any used M3 is a great car but let me give you some advice from a guy that bought a used M3 just as the new M3 was hitting our shores.
I bought a 1998 E36 M3 in early 2001 just about the time the E46 M3 was showing its face on our shores. At that time I was big into dtmpower.net and bimmerforums. Both sites had a dedicated E36 fan base. A lot like E46fanatics and M3forum has a dedicated E46 M3 fan base today. I never really gave much attention to the E46 M since most forums speculated that the bigger, heavier, and curvy E46 M wasnt going to be that spectacular. Also, there were many E36 M3 owners that just didnt want to see their M car de-throned. I guess we all kind of hoped that the E46 M3 would fall on its face and leave the E36 M3 has the M car to own. Of course we all know what happened. Here we are again at the cusp of getting another new M3 and again we have a lot of loyal E46 M fans and others hoping or speculating that the E92 is going to fall on its face. I think history is going to repeat itself and the "nay sayers" will be silenced. If I were you I would hold out another year until a few used E92 M's start surfacing and buy one of those instead. I love my E36 M3 and I cant imagine parting with it. But, had I waited a little longer I could have picked up an E46 if I wanted to.