1. The best company for this is www.stockinthechannel.com2. They have a mangento plugin to import distributor feeds (they have several distributors in the UK and outside UK).3. You can use their Magento plugin to automatically update (stocks, add new products with description, etc)4. The second best company is copsoftware which is in Germany and they have all the German distributors.5. They provide a software/feed but you will need to build some sort of connector to import their feeds into Magento; what i did when i was doing similar setup is that i used stockinthechannel to import my german distributor's feed via copsoftware into stockinthechannel and then from there to the site.