CRE Loaded Modiciations - Create Terms Checkout for One Customer Group

I have a modified CRE Loaded (oscommerce) website and need to allow certain customers to be able to place an order without paying for it at check out. These are a select few customers who have net 30-day terms and will pay me by check later. At present, I have no means of doing so. I am thinking that the site could be modified to allow customers in the "wholesale" group to checkout in this manner--or, preferably, a new group could be created called "Net 30 Customer". The "Check/Money Order" payment module could be used and modified to perform this function. It would need to be renamed and, most importantly, it would have to be available only to this one customer group. Otherwise, a new payment module could be created. That's all. Please let me know if you have any questions.