which rails ready-made solution for a small simple online shop?

I'm looking for a ready-made solution for a small simple online shop.
The requirements are the following:

* It works out of the box
* User-friendly UI: business owner can add, edit, delete products for
sale, their prices, their pictures and their descriptions
* Product categories
* Filtering by category, product name and etc
* Pre-built themes/templates (I'm not good at web design)
* No billing support is required
* SEO-friendly
* Extensibility (addons/plugins)

Any suggestions?

If you’re looking for something completely turn-key, check out Shopify. Yes, it costs money, but it handles a lot of this stuff for you.

http://www.shopify.com/

Yes, Shopify. Or https://github.com/spree/spree