I'm amazed that people still seem to be having trouble finding roms these days. Hell i've even seen working psx isos online (emuchina or chinaemu used to have plenty, from "street fighter ex 2 plus" to "vagrant story") and compressed until they were up to 50 mb and not a byte more!
A good place to find out about websites that have hard to find roms is kaillera, a program included with some emulators which makes possible internet play. There's hundreds of people everyday in kaillera's many servers and most of them know some pretty good sites (after all these guys play arcade/psx/n64/genesis roms online). Go to
www.kaillera.com to find out more.
Here's a site you won't be disappointed looking up by the way:
www.thenationnet.com
I've never seen a broken link in it.