Tommy,
It doesn't sound much different than going the MP3 route that you had "ARGHHHHHHHHHHH".

Don't know how much cash that you want to put out but 1 more thing to look into is Baldoni's custom sounds and rhythms pre-setup in an x4.
UltimateBB.com

I am an accordion enthusiast myself. As Donny (DNJ) said, keep us updated.