Ebay Store Seeking Magento Store to Sync

Project Description:
We have a 15,000+ product ebay store, we need to have a magento web store, have our ebay inventory including all pictures currently hosted on ebay brought into the magento store, we then need the two sales venues to sync so our inventory doesn't sell on one site and remain available on the other (many of our products only have one in stock). There is a magento extension M2EPro that does something similar to this, but it is unable to bring current inventory from ebay into magento, it is meant to go the other way around (list on magento and have it automatically sent to ebay and then synced).

We also need to only list one of everything on ebay, no matter if magento has 300 400 or 1 in stock ebay can only have one of any product listed so with cron jobs we need magento to sync with ebay

Additional Project Description:
03/01/2012 at 0:37 EST
There are certain categories in our product inventory where we can only have 1 product listed at a time on ebay, we need magento to keep all of our inventory but on certain products only qty 1 can list on ebay (even if magento stock is in the hundreds), there are other categories that can be listed fully and we can set this based on Magneto categories.

I don't know if this is too complicated so let me know if you have any questions or if I didn't explain well. We are also potentially interested in a long term relationship with a magento/seo to help run our webstore with us if this project goes well.