I am currently using ZenCart as my shopping cart and I am looking to upgrade to something with more features. My website can be found at www.izillapod.com. I am looking for a shopping cart or shopping cart service that offers lots of features and is integrated. Right now, I host my ZenCart site on my own server and I only pay for a monthly hosting fee. I was able to create a decent template and I liked how ZenCart was easy to customize. However, I want to move on to a shopping cart that provides features such as:

- Integration with all major shipping carriers (at least get rates and possibly print shipping labels right from my site)
- Integration with major payment processing services such as PayPal Website Payments Pro and Authorize.net
- Offer the option for customers to create an account, but not be required to.
- Have a short and simple checkout process.
- Have the ability to add/remove products from existing orders and tweak prices of shipping and total price if needed.
- Offer promtions like gift vouchers/cards and discount coupons.
- Newsletters and emass mail for previous customers.
- Be able to keep the same theme/template of my old site or create a similar one.
- Have different order fullfillment options (drop-ship, stock, etc.)
- When a customer places an order for a drop-shipped product, I want the customers order information emailed straight to the drop shipper.
- Allow customers to track their orders off of my website.
- Have the tracking number sent to the customer when the shipping label is created from my website.
- Have the ability to integrate with sites like eBay, Shopzilla, Shopping, NexTag, etc.
- Offer an affiliate program.

Again, those are some of the main features that I want on my website. So far, I have looked at Yahoo, Monster Commerce, CoreSense, Zoovy, GoEcart. Again, I want something that is easy customize and has many of the features I listed above, but is still easy to use. I already have ZenCart (a spin-off of osCommerce) and I am looking to take it to the next level. I really liked CoreSense, but their minimum plan was $25,000 (i'm not there yet). CoreSense recommended Zoovy for me sense I was a smaller business. Please let me know if you have any experience with the shopping carts I listed or if you know of any shopping carts that offer the features that I want.

Thanks.