Need a payment module for our Xcart shopping cart. Our new payment processor is Zombaio. Their system is designed primarily for subscriptions, but we don't do that, we sell individual products.
The solution must resolve two steps...
1. Adding our existing Xcart users to the Zombaio system
2. Processing the (variable) payment amount based on the customers order
3. Appropriately handling both successful and unsuccessful orders, with some type of helpful message to the end-customer when possible