I use to have the Logitech Momo Racing Force Feedback wheel.
Yes it is supported with GT5 in the PS3. The only cons though is that you cant change the buttons to map them the way you want them and you can only shift with paddle shifters. The sequential shifter does not work at all...
I've tried the Driving Force GT wheel as well from a friend who uses one and I just want to ask, why is it that you dont like the DFGT? In my opinion, I'd go with the DFGT with the Momo unless you're really in a tight budget, dont really care about full compatibility with the PS3 or the 900 degrees.
Your choice though.