Amazon expert -- 2

I am looking for someone to build a tool (or you might have an existing tool that can be adjusted) to track the organic ranking of a list of keywords against ASIN's on Amazon (US market plus all EU markets) Updates would be run maybe weekly, to show the trend of the ranking - either graph or increase / decrease in rank.

I know there are tools that connect to Amazon api, but be aware that this would be ASIN's on different Amazon accounts, where I have user access but not api access.

I am not sure the best platform or programming type for this project, so open to suggestions, but want to keep it as simple as possible. This is for my own use, not to promote commercially.

Please provide suggested approach and either fixed price or hours to complete the project.

Thanks