Amazon: number of sales per asin

Hello, We are looking at building a tool that will estimate sales by ASIN. If possible I would also like to collect data for ASINs out of stock - I am not sure if this is possible? There is a report (amazon seller central) available: reports→business report→detail page sales and traffic by asin reportID=102:DetailSalesTrafficBySKU (to see in the browser line) The report includes: Sessions Page views Buy box percentage Units ordered Which I would like to record on a regular basis - I am not sure if this is obtainable via the MWS/API or if another method is required? I would like to be able to offer other people this tool once built so any solution would need to be replicable. Thank you!