Hi there Victor, that is a really interesting system.
At this time our App Store does not have any Afterbuy integration. For inventory management some good apps are Lettuce http://apps.shopify.com/lettuce and Stitch Labs http://apps.shopify.com/stitch-labs
It is also possible to develop an integration, Shopify does have an API which developers have access to which could work to control your inventory. Are you a developer? Perhaps a Shopify Expert can help also experts.shopify.com/developers