Amazon Products Data Feed

We use Amazon product ads to submit products to Amazon. They accept either our google Base feed (drawn from the products already on our website) in a .txt file or they will accept a spreadheet upload that is within their specific parameters. While we have successfully supmitted our 21,000 products to them using the Google base feed, it is far from optimum as the feed lacks much data that amazon requires to view the listings as optimum and give them good exposure such as PUC code, dimensions, manufacturer, category and too much HTML in the description. We need someone to clean up an create a better feed for us. You would need to use a number of our manufacturer spreadsheets (probably 4 different ones with 3,000 to 7,000 of the 21,000 products each) to grab and coallate the missing data into a single, clean and optimal feed. Much of this work, I believe, will require more in depth knowledge of excel than anything else. After this small project we have a number of large and small additional projects.