Prestashop module/s - share stock level

We need someone who can create the following prestashop module for us: Objective is to have multiple prestashop shops share their stock levels, constructed in the simplest way possible. Simple both in the amount of work invested and simple regarding to the change impact of the shop. Fresh install of latest stable version of prestashop is the work area. Our vision of this project is to create a mutual database where the stock level data is held. The module required will enable a shop to access this mutual database when it needs the stock level data for any given product. In order to keep the table rows in sync with the individual db's it will be necessary to make possible the selection of a product_id number whenever a product is created. Shops with products sharing the same id will therefor operate on the same value in the shared database and thus share the same stock level. If there is a simpler way to share stock levels we are very interested to hear it. Thank you for your time. /Michael Herrero