Compression of PS1 isos

[Zegame]

What is the best format for compressing PS1 isos?

I have a collection of PS1 isos and I want to save storage space and have the file ready when I want to play. Emulators do not read .rar, .zip nor .7z and it takes some time to uncompress the files. I do not want to decompress the file whenever I want to play an iso. The use of .ecm does not discard the use of other compressors.
The .cdz format is read only by psxfin, which is abandoned and unfinished.
Some emulators read PSP's .pbp, but I am not sure if I can convert it back to .cue/.bin, because I want to have the clean unmodified iso and I do not want to use irreversible compression.

Any help will be appreciated.
Thanks.

[Zorlon]

You can convert pbp's back to bin+cue with psx2psp or psxtract

The only ones you will have issues with are official pbp's that don't use the same methods as unofficial pbp's also can't be extracted via PSX2PSP anyway

Alternatively you can try the mooby2 cdr plugin that can run compressed iso's though can't claim to of used it that much so can't vouch for it. (The official site is dead but it is easy enough to find via google)

EDIT:- More info

I know it seems confusing but PSX2PSP does read cue files even though you only point to the bin file, as long as the files are named correctly it will auto look at the cue file for CDDA tracks ect and build a pbp with all the tracks there
So when converting back to bin format you do also get the cue file and keep all the extra CDDA tracks if the original image had any
Best way to know though is just to give it a try instead of taking my word for it