So your trying to link or redirect from your product page to an Amazon page correct?

You need to be careful here as Amazon really don't like the URL showing it differently to the acutal product page URL. I believe its against their Terms & Conditions. They want to be able to trace exactly where the customer has come from. Your re-directs sound a little complicated.

A redirect automatically sends your website's visitors to a chosen destination, either a different location within the same site or a new site entirely. For example, you can redirect visitors from your domain root to a content sub-directory, such as a blog.

Content (files and folders) under the redirect path can be redirected to the destination domain root or the same path on the destination domain or not redirected at all.