68975 Zencart frequent shopper??

My client needs a 'Frequent Shopper' style program added to her Zen Cart store. Shoppers MUST sign up for the program and spend over a certain amount. They will be snail mailed a gift voucher for the store, but she needs a script integrated with the zen cart to notify both her and the customer that they have qualified for receiving the voucher and that it is on its way. Basically she wants the customer to have to spend AU$250, and then she will post them a $25 voucher. She doesn't want to have to manually figure out who has spent what, just receive an email with their name, address, amount spent, and then she can send them the letter. The customer would also receive an automatic email from the cart saying something like 'Congratulations, you have reached $250 worth of purchases, a $25 gift voucher is on its way to you in the mail' (etc, etc,) And then for the customers order total to be reset to zero so that future orders also count towards another qualifying period of $250.00 Payment via scriptlance account only.