eBay Shop listing template with book pre filled data

This is quite a specialised area of eBay so I only want people with experience of exactly this type of project responding. Please do not bid if you have not had direct tangeble proof of doing this. My company trades high volume items on eBay, we sell books. We sometimes have up to 750k listings on eBay. Currently our process for listing products onto eBay is this; We generate a stock list of all books in stock, this provides us with a list of ISBN's/EAN's and retail prices. We insert this data into an eBay 'File Exchange' template. We rely on the eBay 'Pre Filled Item Details' which are generated from the ISBN for the item specifics. The body of our description on each listing is actually just our terms and conditions , logo and a little about us. It is identical for all listings. We currently have this 'description' as a .jpg because if we had HTML for this listing our File Exchange upload files go from the maximum 15mb to over 200mb per file. Unfortunately eBay have expressed their dislike of me hosting this description 'off site' as theoretically we could change our T&C's after an item has been listed. We have also now got that many listings that we are getting a lot of failures from eBya not having the 'Pre Filled Item Details' even though the ISBN is correct. There are two things we want to achieve here; Firstly; We want a solution to the listing template issue. Ther must be a way of having a set template so that I do not need to use File Exchange to uplaod how each listing will look. For example, look at each of these listings; [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] All of these sellers have a similar amount of listings to me and they all have their T&C's laid out on each listing. How would they be doing this without needing to upload them per item? Secondly; Looking at the items above again, the listings also have the book data inserted into the listings. This is not reliant of the eBay pre filled item information. I would like to know how I could create a similar style of listing with the book data generated from my ISBN's. I realise that I may need to pay for a license for this information from a third party, I am happy with that so long as the data is reliable. What is more of a concern to me is getting all of my books listed without having to rely on eBay having the data. Looking around eBay I see many sellers with over 1 million active listings with complicated descriptions so I am sure that there must be a way of doing this! I would also be looking at creating a more professional listing template but this would be dependent on the solution to this problem. Please only respond to the project if you have direct experience of this.