I would stay away from anything InterAct. I had an InterAct Saturn memory cart a few years ago and had nothing but problems with it. I lost nearly two years worth of saves. Also, it worries me to see people wanting to hook up a PSX controller to a DC. I can only think that you must have started console gaming with the PSX. PSX controller's suck in my opinion. The d-pad makes the thumb sore and the controller doesn't sit all that great in the hand. Reminds me too much of the old NES controllers. The Saturn analog controller is, by far, the most comfortable controller I have ever used. Wish Sega would have stuck with that design for the DC.
-DAGTA