Being "versatile" as I am is the best of both worlds IMO.
The majority of the fem boys I've been with have preferred the bottom role - and the str8 (or str8 types) usually prefer top, but as several of you have pointed out that's not always the case which is perfectly understandable.
By-the-way: If his sexual preference is a deal-breaker for you don't bother asking him what he'll do in bed before you off him - just tell him what you do in bed before you off him. Works every time.