Hello,

I have a simple shopping cart application running right now, but was looking to upgrade to a better shopping cart package. I was hoping to find:
* application that is easily indexed by spiders
* coupon codes
* quantity of product available
* gift certificates
* customized email messages for order confirmation
* wishlist feature (so customers can buy later)
* customized checkout asking customers if they want a free samplers or mousepad on checkout?
* pay for downloads (like payloadz.com)
* customers can login to their account
* work with current Linkpoint gateway, PayPal, and GoogleCheckout possibly for mail-in orders

Mivas looked enticing, but didn't support googleCheckout and didn't look as modifable as some other cart options. I was looking at AmeriCommerce and volusion, but have 1,000+ very small product variations and hate to have to pay $3,000+/year for leasing the service. I would prefer to purchase a cart for one time fee and have it hosted on my existing server.

Does anybody have any recommendations for a highly customizable shopping cart with such features or other suggestions?

Thanks!