zumanity

I am currently building a website to sell my product. I have built websites using WYSIWYG design editors via Yahoo and have used their ecommerce hosting packages, but is there a more preferred method. Shopping cart options? Purchase shopping cart software? Or buy into an ecommerce hosting plan that has the shopping cart included. What questions would I really ask myself in order to help narrow down the field of choices when building an ecommerce website? I've also used osCommerce before and found it a bit limiting. Is there a one stop method that handles everything from shopping cart, credit card payments, client records, auto responders, merchant accounts, SSL etc?