I didn't realize that Amazons cart was like this, but then I have never ordered a product with attributes from Amazon. I think modeling your self after Amazon is a good idea. I also understand the difficulties involved in adding edit functionality with attributes. I am currently working on a uc_attribute / kit bug.

That said I sure would love the functionality. The store I am working on now uses flash to preview the attributes, so I would be some additional challenges for me there as well.

Thanks for the the theme hint. That gives me a quick option.