Shopping Search Engine website help

Hi there!
I am starting up a new website that will be similar to tagjag.com but different in some ways. It will allow the shopper to search all products on all the major shopping sites, view photos of the product on all the major photo sites, ad reviews all big video sites. My question is, how would you go about making this search engine. For example. Let's say I searched for "iPhone". What code would I use to automatically edit the amazon link for example from http://amazom.com to input http://www.amazon.com/s/ref=nb_ss_gw?url=search-alias%3Daps&field-keywords=iPhone&x=0&y=0 ? I would want to do this for all major sites. Thanks :)