You can D/L a nice mix of PSX, N64, PCE, and more at this site. -Link removed. Read board rules.- And here is a link to get BUG for Sega Saturn if anyone is interested. http://intermega.com.br/raulikoo/Bug!.htm
I'm not sure about the architecture of the psx control pad, but there is a PSX controller to PC USB converter. It can be found at some radio shack stores for about 10 dollars. You just plug in and play.
Happy to help in any way that I can. This is a great site that is about helping everyone, and very n00b friendly which is very refreshing to see. Kudos Gamecop!