I think an M3 sedan is fine. Kind of like the family man Sports sedan, but below/different than an M5. I haven't driven an E90 M3, but from driving 335i E90 and E92, its a very similar experience. Just a matter of if you want the extra doors really.
Current 2013 BMW 335is E93 [Mineral White] [Coral Red] DCT, Premium Pkg, Convenience Pkg, Nav, Heated Seats, HK, BMW Apps
Retired 2007 BMW 335i E93 [Sparking Graphite][Coral Red] Steptronic, Premium Pkg, Sport Pkg, Navigation, Active Steering, Logic 7, Comfort Access, CF Trim