Build me a website

We need to get a new website built to replace our existing one. Our current site is not SEO friendly and can't handle many of the things we want to be able to do. I have done some research on e commerce solutions and I think the Big Commerce seems to have the best combination of everything we are looking for. We want the new site to be able to handle 360 degree spin photos, user reviews (standard function in big commerce), PDF uploading capabilities, Bulk Product importing, Payment and Shipping collection and have all facets of our site editable through the admin panel. I am fine with using an existing theme, we do not need to do a custom design as long as it will work with everything we want. I am most interested in keeping the cost and time frame reasonable. I am most interested in a design which will maximize conversions and return on investment. We plan to do PPC advertising initially and may do SEO on the website later on. We currently have a WordPress blog on our site, so hopefully that can just transition over easily, though it is a new blog, so there isn't much in it anyway. We plan for the site to be free shipping, but for orders smaller than $50, it would need to use UPS rate tables to calculate shipping by weight and zip code. For payment solutions we will be using [login to view URL] since that is what we currently use. I have not yet decided where the new site will be hosted, it may be with our current website hosting service. I will decide that before we begin. I want the new site to be able to also easily handle images by automatically resizing them for thumbnails if possible (our current site can do this), and yet still retain the full size image so that customers can click to enlarge them. We would like it to be able to handle gift card codes that we plan to use. And it would be nice if we could somehow highlight some of our products so that the customer knows that those particular products can ship next day (kind of what Amazon does with using the Prime badge). Our products have many options which the customer can choose from such as the door design, frame design, color, hardware, custom sizing, etc. so the new design will need to be able to handle all of those options.