Hiya Flickstah!
Our affiliate software allows you to add multiple sites, and we're offering free cascading billing integration with any ecommerce solution that you're already using on your site.
Rather than being a script that you install, we're a service based software that you simply link to from your site. Affiliates are able to join your program from your site and choose one or all of your sites to promote... and we pay affiliates for you.
Let me clarify about the cascading billing, because it sounds like you may be looking to kill two birds with one stone: we don't send visitors to alternate payment options for you, but are able to track results for the billing solution(s) plugged into your site.
You can check out a demo here:
http://taboorevenue.com/page/demo
Fyrflygrl