Custom Magento Plugin

We have a magento store (1.9), when we add products to this store, we want it to update a second database with the new products. This second database is used by a custom POS system. Anything you write in the magento code should comply with the follow: 1) Updates to Magento wont break this code (so you may need to code it as a plugin) 2) The magento site does not break if it is unable to add the product to the other database for some reason. 3) An error notification should be made like a popup if it was not successful in adding the product to database when saving it from magento. So we know if it did not push the product to the POS database. 4) Price info and all details from magento should be imported to the POS product tables matching magento (e.g. price, special price, description, title, etc). *** Need this done within 3 days *** Please do not bid if you have not fully read and understood the project.