You might want to try the
Final Fantasy Settings Thread. Try those settings, they should work. And it doesn't really matter which version of FF7 you are using, i am using the pal version (which i bought, okay BanjoK?) and it works well enough. Of course you still get annoying slowdown in the battles and the music (arguably the best part of ff7) is tough to listen to...
But it works well enough...
I have some free time coming up myself, i think i might try and port over AdriPSX. It had good compatibility back in the day and low requirements...
Anyways, check out that thread...