Amazon and Ebay price comparison site

I am looking to develop a responsive, price comparison website for Spain (I have the layout, but it has to be tweaked...[login to view URL]). It will focus only on Amazon & Ebay (Europe) products, and not have a database (i.e. be based on feeds) Clients use dropdown lists and autocomplete searchbox to find their product If any of the select boxes are used when there are results on the page, then the results should update automatically The searchbox should consolidate dropdown lists from Amazon and Ebay (showing item name) When client hits "submit": Option A (there is only one item relating to the search term): Go to Results (below) Option B (there are many items relating to the search term): A scroll box should appear next to "submit" button, showing all items with the same name, and the quantity (if names are the same on both websites, they should be consolidated) All of these items should be prechecked (the results will show below) User to use checkboxes to deselect many items (also have a select all/clear all button) from the resulting list, and the results automatically refresh Go to Results (below) Results URL should change to include search term Output from both websites in the relevant boxes, to show product name, photo, price,location. All in an infinite scrolldown list, with top 10 visible Both lists should be ordered by the price (lowest first), with a total at the top If product name and price is the same for many products, then show all If product name is the same for many products, but price isn't, then show cheapest The price is the asking price + total shipping cost (the cheapest shipping option possible) in Euros. Ignore coupons and special delivery options If it is an auction item, then also include time remaining If it is a used item, then also mention this Clicking on item will take user to that particular item on Amazon or Ebay webpage Backend System to manage feeds (also option to add new feeds from other websites, select fields for output on webpage) Consolidator system (for example if user enters "TV", then "television" results are also shown) Need database setup to change languages NOTES: Amazon Pricing: Include these types Amazon listing featured price Lowest price for new product Too low to display: you have to go to [login to view URL], add the product to shopping cart to see the price? Exclude Amazon items which are "Currently unavailable"