If your PS3 can have custom firmware installed on it, you can package the disc contents as a fake PSN game and play it that way. I haven't messed with CFW in a while, so I don't know how much has been cracked in terms of exploiting newer official firmwares and different PS3 models. I'm sure the hackers are catching up as Sony's support dwindles, though.
Other than that, buy a used PS2 or use the PCSX2 emulator, I guess. The last time I tried Suikoden 5 on PCSX2 it ran like molasses in January, but I'm sure it's much better by now.