i have a momo millenium 320mm.

its a lot of fun. when i was shopping for a steering wheel, one factor i was looking for was a thumb knotch.....if you look very closely at 9 and 3 o'clock on the steering wheel, theres a little ledge/knotch for your thumb. its REALLY comfortable. the Sparco LAP3 and LAP5 are also very comfortable.
i might sound stupid, but when you have a 320mm or just any smaller steering wheel, i often drive with both hands just to get better control because its extra sensitive to small movements.
i'm sure you are aware already, but not a lot of after-market steering wheels have air-bags on them---only a horn.
and when you get steering wheels, you also need to get a steering hub as well.

g'luck on your decision!