Magento

In our business, only certain customers can pay via certain payment methods: for a customer to pay, say, via invoice based on Sales Order, they must contact a Sales Rep and once approved are permitted to pay via this method.  We would like to enforce this model via Mage and think a natural mapping of this is to have a Customer Group select list as part of each payment method’s System Configuration.  Then, only the payment methods available to a customer based on the group they are in would be displayed in the Payments section of the single screen check out.