I have implemented a new zen cart (v1.50) site with a custom template.
I have installed some 'add ons' including "minimum_order_amount_1-2"

With this add on, the site is now set up so that all orders must be over $50 to allow checkout.

Now we have a situation where we want one customer to purchase without needing any payment (credit customer)

This customer should also have access to some extra products that are not available to regular customers.

Is this possible either by configuration of the current system or with an extra module?

Any comments/advice would be welcome.

TIA