Or does anyone use another processor besides Paya?

Most of my clients use Pay Invoice from Skyline, it completely integrates so when a customer pays the invoice it will come back into Sage as a cash receipt and mark the invoice as paid.  It will batch out the CC batch at the end of the day in Sage automatically so the bank rec is easier.  It will send past due reminders to the customers per whatever settings you want including a pre-warning the invoice is coming due.  You can also store and run the cards like Paya as well.  You can also receive a pre-payment from the Sales Order and that will come into Sage automatically as a customer pre-payment.  So it has a lot more features and they can shop the rates so you will pay less than Paya.  I can send you a link if interested.  [email protected]