One step in this direction is a mod of mine called, Skin Swap, it will allow you to easily change skins off a single X-Cart store and rebrand it however you see fit.
More info:
http://www.cart-lab.com/lab/customer/product.php?productid=1
This mod won't allow for multiple payment methods for each provider but rather makes it easy to rebrand the same store/data with a new skin layout. Just to clarify.
