Take a look at Zencart.com, completely free e-commerce platforms, very easy to understand admin to set-up your shop, and there are plenty of template options to skin it.
You can check out templatemonster for those, but they are quite easy to find elsewhere if you prefer.
Zencart also has a handy little forum where you can get good assistance, and even find developers who can set the site up for you and make some custom alterations if required.
You will also find plenty of free mods to add on to your program on the site as well, so well worth a look if you're going down the path of an independent website platform.