Custom Website Design with Javascript Calculator and Shopping Cart

We are looking for a programmer / design to complete our project from start to finish. We currently have a site :- [login to view URL] - which sells CUT TO SIZE glass for fires and stoves. So the site only sells ONE product which is glass cut to the size the customer specifies and our calculator works out the price for them. We want another site to do almost exactly the same thing, except it will sell cut-to-size fire bricks instead of glass. The site we currently have now, uses a javascript calculator to calculate the price of the glass, this then is added to a Joomla (Virtuemart) shopping cart, where the customer completes the rest of their details and pays by Paypal at the end. We want you to design the site, the calculator, setup the shopping cart, everything to make the site work from start to finish. The site will have the following pages : Home Page, Contact Us, About us & Order. We will supply all the text for the pages. We are looking for a programmer who can design either adapt / use the existing javascript calculator (we will just supply a new cost formula) or create a new one, which will be exactly the same as the on the above site, but without the radio buttons (plain glass, clipped corners, shaped glass) that calculates the price of a firebrick, the customer will then add this to some kind of shopping cart (we don't mind which one you choose), they will then complete the checkout process and be able to pay by Paypal. Please ask us any questions you need to know before you bid! So, basically, you will be given the domain and FTP / Control Panel access and when you are finished, there will be a new site designed a calculator created / adapted from above and integrated with a shopping cart and the customer will be able to purchase a custom firebrick. Please do not bid if you don't have any previous feedback on scriptlance. Please respect our budget.