There are tons of guides out there, and I am not the best to explain it, since I did most of the stuff way back, just look up "PS3 Ftp" or "Filezilla PS3" on YouTube or Google.
BTW, you can also emulate PS1, PS2 and PSP games on PS3 by putting them into PSXISO/PSPISO/PS2ISO folders, that works even from flash drive.
Also for FF13, it's on sale 60% off on Steam right now, as are most Square games, unless you want X360/PS3 achievements instead of Steam ones. Can also pirate it on PC but that will not have achievs. It's really what's more convenient for you, I played stuff on console because the couch is more comfortable until I set up Steam Big picture.
Starting with FF7, all PC versions of FF games have updated Steam versions with achievements, most with built-in cheats for no-encounters or speed-up and modding support. You can connect an XBox or PlayStation joystick to PC too and they all support controllers tho getting PS3 gamepads to run on PC is a bit fiddly (others should work out of the box).
See what you'll find easier, getting a gamepad to work on PC, or learning to upload games onto PS3. Both things are good! XD