Build an Online Store

First Project 1: Responsive E-Commerce site built on WordPress with shopping cart and secure checkout/payment. There will be over 1000 items for sale, each unique, but each in one of 25 categories, or sub-categories. Each item will have between 3 and 9 pictures. Want ability to sort items in a category by price or date added, as well as the ability to have items in more than one category simultaneously. Want each item whether sold or not sold to have a permanent URL.\r\n\r\nHere is a website that comes the closest to what I want: [login to view URL]\r\n\r\nProject 2: I\'m uncertain if this is even feasible. Currently, I\'m viewing Project 1 as a new site with new domain. However, my current site has very high domain authority with thousands of inbound links. I am therefore wondering about the feasibility of doing thousands of 301s, but that would be a separate job, I think. Current site was built and maintained with Dreaweaver 4 without CCS since 1999. It has an enormous amount of highly scientific and copyrighted intellectual content. The question is whether moving content is possible, and whether all the 301s will damage current SEO.\r\n\r\nFollowon Projects: I have more old HTML sites that are all content and not e-commerce, and would update to responsive technology if feasible and affordable.