Just about every emulator uses the .mcr format for memory cards, or one that can be converted using PSXGameEdit (freeware). ePSXe, PSXeven, and sssPSX all use the same .mcr format.
Did you hold the disk up to a bright light to see if you can see light shining through scratches or pinholes? It can be hard to see label-side scratches otherwise. Another suggestion for checking your disk quality - run it through Nero CD-DVD Speed (freeware) or, if you have a Lite-On drive, KProbe2.
You might also want to try making an ISO of the disk and playing from that, though it's important to make an errorless one. Whatever image ripper you use, you should set it to NOT ignore errors, retry as many times as it can on making an error, and capture subchannel data (in case it's a game with subchannel-based copy protection).