Partners who are also customers

We have a number of customers who are also partners (classic referral program).  I have created two separate records for them, one for the customer record and one for the partner.  They are listed as partners on the transactions they referred.  Now on to the fun part - how to pay them?  What I want to do is create a credit memo so I don't have to write them checks, but because the deal is related to the partner record and I bill the customer record I can't do this. Does anyone else have this problem, and have you been