That sounds like quite the adventure!
Let me start off by telling you a little about us...
We have been working with Shopify since their inception over 3 years ago. In addition to building two free themes (http://vogue.myshopify.comand http://moderno.myshopify.com) and in excess of 60 client sites, we have also built a web application that ties directly into Shopify (http://www.fetchapp.com / http://is.gd/3aiSD) allowing customers to sell digital goods. Shopify has also just hired us to build 4 more themes that will be issued as default themes. This will be a total of 6 themes we've built directly for Shopify.
In short, we know Shopify and what is possible, or how to make something possible.