Magento

I have some unique needs for my store that I’m hoping Magento can handle.  I sell precious metals (gold/silver bullion) and so most of the time my orders are in the tens of thousands of dollars, but since my margins are so slim I can’t take credit cards as a form of payment.

I would like to get cc info from each customer and keep on file for 2 reasons though:
1. To verify user identity and ensure that I’m on side with all FINTRAC regulations, and
2. To be able to charge a cancellation fee in the even that a customer doesn’t pay for their order and I must liquidate it at a loss

First time customers should have to provide a credit card before being able to submit an order.  Credit cards should not appear as a payment option however when they go through the checkout.

I’m new to Magento so I was wondering if anyone can suggest a payment processor and how to go about setting up Magento for this.  I see that it supports Authorize.net, would that be the best way to go?

This wouldn’t require a payment gateway, as you’re not accepting card payment. It would be a custom built step in the checkout process, separate from the payment method.

Wouldn’t I need a gateway in the event that I need to charge a cancellation fee?

A payment gateway is only required for immediate payment. I haven’t come across any gateways that take credit card details and save them to be used in future for a cancellation fee.