Star Ratings Plugins for Product Reviews

Hi, I’ve got an affiliate only product review site (no shopping cart), using the Responsive Shop Theme, and I like GD Star Rating for individual products, but I’m aiming to have sidebar widgets that have Best Rated Backpacks, CD Players, Computers- all different Categories of Products. I can only find a way to have a widget that combines all categories, which is pretty useless because I don’t want backpacks compared to computers. Does anyone know how to pull this off? Is there another plugin that will do it, or custom coding resources? Thanks, Jennifer