What are your thought of
Raphnet? They make PC adapters for various consoles.
I've got this silly idea of getting a
Race Controller as well as their
Dreamcast adapter to play Sonic Racing: CrossWorld with, despite the fact I'm not that into racing games.
I mean, it's not like Retro-Bit's Sega Collab' covers controllers other than the standard ones for Mega Drive, Saturn and sooner-or-later Dreamcast. But buying a Raphnet adapter and a Race Controller would be around eighty quid just for the one racing game.
Other than that, if I get too many controllers, it's a matter of where to put them when not in use.