Purchase module for certain customers?

[invision]

I'm looking for the ability to allow certain customers to purchase without paying with a credit card -- i.e. a purchase order or pre-approved account. I see a mod that allows purchase orders, but does that do more than just add a purchase order option at checkout?

I don't want the PO option to appear to everyone.

Sorry if I've posted this in the wrong area.

[swguy]

The invoice module in the downloads section provides a payment method called "invoice" that only shows up for customers in a group whose name begins with "invoice."