A few more scripts you may want to try include:
Affiliate Niche Script - A scipt allowing you to build an affiliate store combining both the Amazon Associates and eBay Partner Network programs. This option is not terribly expensive (unlimited license for $97), and is designed well out-of-the-box. If you have a bit of web design knowledge, you will end up with an amazing looking website. The feeds for this script allow you to also mine ratings and reviews from Amazon.
Fresh Store Builder - This script is a bit more expensive ($297 for 3 licenses, $29 per license after initial purchase), however it is much more versatile than Affiliate Niche Script when it comes to design and customization options. From a usability/admin perspective, this script is phenomenal. Also, checkout for Amazon US affiliates is integrated - making it likely that conversions will be better.