Opencart v1.5 automatic stock & prices sync from FTP

I need an extension for Opencart 1.5.6 to periodically (e.g. every 10 minutes or less) check for products stock and prices which are stored on the FTP server based on SKU and sync them with ones in the Opencart database. Sync is only one way, so from FTP to web store. Database is stored in .txt files, similar structure like csv (value1 | value2 | value3). To visualize better, the database from the FTP server is from a physical store. Keep in mind that in some cases the product is actually a product option, in other words, each product option has it's own SKU and they also need to be matched with the database on FTP. If extension cannot match (doesn't find) a product, it should logically ignore the change, but it needs to log errors alongside a complete log, so I always have a transparent view if there's a problem. There is also a case when manual price or stock change is required. The extension should therefore support a manual override - so to turn sync off for a specific product. Since some of the products will only require stock change and not price change, there should be an editor in administration panel to simply select and deselect which product and what should be synced. I think if that's implemented into Catalog -> Products, that would be the best. VQmod is preferred, so I can update Opencart and theme in the future while retaining compatibility. Let me know your view on implementation. Please don't set placeholder bids, but realistic bids. Also state how many days do you need for completion.