Depends on what you mean by cheats.
You want some button combos? There are none.
You wanna change the programming around? Probally snag a PS1 and an old old old Gameshark. You could probally use a PS2 Gameshark, but I'd imagine it would require completely new codes (Being not of a hardware difference, but software difference. Different versions require different lines for the same game).
It's possible. Only feasible way to get Aeris back too after she dies (Dont believe the hype, you can get her back).