There are no PAL machines. Well, no real PAL machines. It was never released there. If you have a "PAL" machine, it's actually a TG16 outputting PAL. That means US cards work. Or if its a PCE outputting PAL, jap cards work.
To find out which hucards you can play, I suggest getting a cheap hucard of either US or JP region. If it loads up, you know what you've got. Otherwise, assume if you unit says Turbo anything, it takes US cards.