All ps3 can do ps1 and ps2 games since cfw etc. Some native some emu.
Maximum drive size is 1.5tb and you can do a 2tb to 1.75tb trick like on psx-place. USB 2tb and maybe bigger with prep ntfs I dunno havent tried.
Do you know how many PS1 and PS2 emulators are there in the latest FW installed in a PS3 Fat/Slim/Super Slim? Sorry, this is very confusing. What about the PS3 with HAN/HFW/HEN installed?
Also, can one choose the PS3 emulators he/she wants to use, how many emulators are there for the PS2 and isn't there a PSP emulator?