So, I cannot figure out how to work Mednafen at all.
Few things to consider Griff: you would need 3 bios files in "firmware" folder for PAL/NTSC-U/J machines, then open Mednafen CFG file with any word editing software(like Wordpad or MS Word), scroll down the list and about midway through you should start seeing PSX settings. Tweak those according to this guide (scanlines, bilinear interpolation, screen filters etc.). Hold down 'alt+shift and press 1' while emulator is running to map the controller buttons(press it twice each for them to register), drag and drop CD image on Mednafen .exe to launch the game. F5 save state, F7 to load, some other keyboard shortcuts here.(scroll down a bit)