Emulation Help

I am only interested in getting a PSP to emulate SNES games (though if possible I'd like to get NES, GB, GBA, Genesis, and 64 games on there as well), but I have no idea what process needs to be done in order to make this possible.

I apologize, knowing this question has to be asked a lot, I've tried looking around the forums but this has me horribly lost on what to look for.

I just want to know if I need to hack a psp, what model of PSP I need, and what updates will make it impossible for me to run.

I have acess to a lot of PSP's at work, but the oldest update we have is a 3.8 on an original PSP, will that work even?