For the complicated option (I have not tried this btw :) get one of those backwards compatible PS3s and make it dual bootable with Linux, run PS2 games on the straight ps os and maybe other emu's on the Linux boot?
:) I see youtube videos of people doing some of that but don't really know if the whole thing is possible. Might be fun to look into though if you have too much time?
edit: and maybe you could try to find an broken PS2 to just use the enclosure, take apart the PS3 and fit it into the PS2 shell. Voila! A PS2 made out of a ps3! :)