OK i'm doing the savestate stuff now. Looks VERY easy.
I may look at puae later, but the state of that project is in a mess, and it may have changed too much for me to be able to merge in the PS3 specific code. As I said above, I can't really code in C/C++. I'm just good at copy & paste and guesswork. I learn as I go along.
Edit: OK. Quick savestate loading/save added to menu and confirmed working. It's fairly crude. It doesn't support multiple games unless you overwrite the file. I.E You can't have multiple savestates (yet. I can add slot 1/2/3/4/5 etc.. later, then you simply keep track of which slot for which game).
Edit2: Added option to change save slots. You have 9 slots. 1 slot per game.
Edit3: Default save slot files on HDD if none specified in uae.cfg
Will release when done touching up/tinkering. I'll have a look at the github changes too and put in the NTSC fix.