Shopify & WooCommerce Integration

I have a client that wants to leverage the backend of Shopify, but also use WooCommerce as the front end for it's versatility.

Does anyone have any tips/tuts/plugins/thoughts on how best to integrate Shopify & WooCommerce

This is as close as I've come to a solution so far . . .

http://docs.shopify.com/manual/configuration/store-customization/page-specific/cart-page/adding-to-the-cart-from-a-remote-website