It sounds like you're looking for a for a custom or repackaged version of Resident Evil 4 meant to run on PSP via emulation (like PPSSPP) or a modified console, using ISO, CSO, or ZIP formats.

Here's a sample feature set you could use for a forum post, readme, or mod page:

CSO is a compression format used to shrink PSP ISO images. This was popular among PSP users to conserve limited storage space on Memory Stick Duos.