I think one of the best resources for a drive capability is the CloneCD Hardware Requirements
Great drive. Can read and write almost all protections but does not support SafeDisc 2. PSX should be no problem. Too bad is has no burnproof technology.
Is has the same capabilities but is has no Burnproof technology either (at least none that CloneCD supports) which is a big disadvantage when burning at high speeds...
Same as the Ricoh...
I would go for the Sony... However, Ricoh and Mitsumi are basically the same and are also very good drives. The choice is yours