Zen, Payment Gateway and Shipping

Hello all, this may seem a little unusual.We operate a homebased studio with sales and service. We use Moneris as our POS however the system we have is instore only not online. I would like to be able to offer our customers a cart online where they can order their items and services, we can assemble then they can come in to pay using our POS here. (So in fact I am asking can Zen Cart be used strictly as a shopping cart function or do we need to access a payment gateway and shipping option when it goes live?)
Down the road, when our Moneris contract runs out we will incorporate a payment gateway etc. online. For now we would like to give our clients the option of shopping online from thier home even though we are local and picking the order up.
Thanks for any help.
Wendy

There is a COD payment module built-in to Zen Cart, as well as a Store Pickup shipping module. These should suit your described needs.