Custom Programming (PHP, Virtuemart, Joomla) (oas)

I need to sell gift certificates through a Virtuemart shopping cart (Joomla). I'm not looking for gift certificates for an online shop sales; it's for a bricks-and-mortar business. For example; selling an instant gift certificate for a massage or haircut. Simply put, I need this feature: 1. User selects gift certificate amount 2. User goes through the check out and selects a shipping address/ billing address/ Payment/ etc 3. User pays, then, receives a custom email or a link to a custom gift certificate that’s uniquely numbered and watermarked somehow. This is their gift certificate, which they print out and walk into a store to use. 4. The store clerk should be able to log into Virtuemart backend and match the amount with the unique number to verify the gift certificate. Possible? Cost?