I operate a brick and mortar bookstore and sell online as well

 I have one software package that I use to keep my online listings on Amazon and all other sites synchronized (if I sell on one site, the item is automatically removed from the other sites).  I'm going to be going into another line of business that my bookstore software won't support.  I will be listing the same item at a fixed price (not an auction) on eBay, Yahoo, OnlineAuctions.com, eBid, etc.  and I'd like to know if there is any third party software available that would allow me to enter my item information one time (including photos) and then automatically upload that information to all these various sites (and keep it synchronized as items sell or are updated).  Thanks for any help you can offer.