Price Comparison Site

I am creating a Price Comparison Site for a certain type of product, I want to include 10 merchants via either datafeeds and or API whichever the merchants provide, and provide room for future expansion. I want this price comparison service to be similar to [Trademark masked], or shopzilla, or [login to view URL], it must run FAST. I want the site to have Ajax features on the search result pages. I want the site to include SEO pages for each product listing with an excellent interlinking structure, I can provide more specifics of SEO I want. It should also have a great sitemap. The site will also the ability to review products and have them shown under the product pages. Site design needs to use web 2.0 ideas while still optimized for SEO. Have an interface to update the merchant data or a folder to drop a file into that will update the merchants data. Lastly I want to have an article repository where I can dump plain text into a database field on the backend, and it will then create a nice formatted article linked in the front end for the user. -I will provide all the merchant information -I will provide examples of similar sites and competitors -All code with belong to me -Good communication via email, IM, Skype - The purpose of this tool is that a user that wants to find the cheapest price for a certain product, can easily do so. With many refinements. -Please let me know what languages you plan on using. - If this is possible, private message me your understanding of what I want. I don't want any bugs in this tool, I want to be confident that you know what I'm talking about. This job could have future work possibilities.