I've created a patch just now that will take a US version and convert it to the sound restored European version (that's the only way to do this honestly). I can't test if it works right now other than on my PC as I don't have access to my Retron at the moment but technically it SHOULD work.
http://www.mediafire.com/download/mu1w2 ... ration.ipsAgain this is the only way you're going to be able to play this on your US version. The creator of the hack claims saves should be compatible across all versions but quite frankly if not, the only person that can recreate the rom hack for strictly the US version is the original author of it.
Please report back if you can. Also as this patch is rather large whenever you start the game with the patch on please wait before pressing anything and let the patch fully load. It might have to sit at a black screen for 5-10 seconds.