What do you know about Kickstart? http://www.kickstartcart.com/
Looks like it's intended for ecommerce sites that are planning on selling alot of products. It has the features you mentioned, but if you're not going to sell alot of items you might be paying for more than you need.
It's got a 30 risk free trial, so I'd go with that to evaluate before you buy. You'd have to buy at least the Basic plan to get all the features you mentioned. It doesn't mention a set up or hosting fee. Seems expensive to me to have to pay an annual fee for their services, when you could have a shopping cart built from free open source code, integrate it with PayPal and not have monthly fees.
If you want autoresponders and a mailing list, you may already have the capacity on your current webhosting plan. I'd check that first.
If you want a mailing list, that's more sophisticated, i.e., in html look at www.ConstantComment.com or I use www.EzineDirector.com because it will allow you to layout your newsletter to look exactly like your website, plus it archives back issues and gives you stats on who reads your newsletter.
Thanks for Asking!