I would take greedyboy's advice and get a designer on board. I thought of using frooition myself as their portfolio is very impressive, but after seeing the prices I don't think any design, no matter how good, is worth the money. Unless of course you have the money to spend, even then however I'm sure you can find something equally as suitable cheaper.
I am in the process of having a logo designed with the aim of using the same designer to custom design a store. The people I am using are called 'professional website services' and their prices are pretty much unbeatable. Below is a link to their ebay store in the US, if you look at some of their store designs, they are quite basic but have all you need, and in my opinion look pretty impressive, especially for the price, just $99.
Hope this helps.
http://stores.ebay.com/Affordable-We...nd-Logo-Design
p.s. Im not related to the store in any way, just think their service is a good deal