A custom plugin for product comparisons on my site

I need a custom plugin for products comparison in either drupal or wordpress platform. The products details will be pulled from various datafeeds (about 6 to 7 feeds) available from the affiliate network. In short, I need something that can do the SAME type of job as giftcardgranny dot com and cardnap dot com plus a comprehensive search engine (like keywords, product name, categories) for the products with price, discount filters and etc plus an email alert function. This job also requires some design for a new theme to go with this plugin. I already have a site, but it's running on a wordpress. I am looking to complete overhaul the site to give a better user experience. I am looking for the site to be very user friendly easy to read and use so users can get the information they need without hassle. I prefer only one milestone for the whole project and will only release it when the project is fully finished and done right. If you have any more questions about this project, feel free to message me. Thanks,