Thanks so much for your help Magic! I was fearing that was the case. (No available templates and difficult to edit existing one.)
If you're reading this WebAssist people - a layered .psd file of the power store layout and buttons would be cool to include in future releases. Most other template places include that in their purchasable templates. (Not everyone is in love with the WebAssist blue...)
I'll try to post more details as I reverse engineer the store template with a link like Magic's link.