Suni just announced a retro pan product to make existing photo pans digital. I have not seen the product and I don’t know what it costs. It looks interesting however previous efforts to retro fit existing panos have been limited.
For now I suggest you sell or donate your photo pan and just go digital. There are several direct digital pans for about $30,000 including Kodak, Schick, and Gendex
The Suni web site does not have any details on this new product, such as cost etc, just a press release here: www.suni.com