What search engine to use?

[Jake]

The problem is probably on your side, not the search engine selection, you may be somewhere in the back pages of the search results among the thousands of other sites that can't match the ranking power of Amazon or other major sites.

Your literally targeting product searches suggests an over simplified approach, to gain ranking better than the numerous other sites using the same Amazon catalog data feed you need lots of original content as well, like a series of photography articles on a site with camera links.