I don't have any info on the motor for you but I wanted to mention something about the servo's. You can get drivers for them that work with a Mesa card for conversion to EMC and the encoders output sine waves but if you take the encoder control card out of the Heidenhain control (if you poke around you should be able to find the details as one guy did this) it outputs standard signals that you can then just send to the Mesa card.
I really like the machine (I actually have 2) and am planning to convert one of them. It should actually be pretty cheap, just the mesa card and servo interface. Anyway just some thoughts. I have to get one of my spindle motors fixed as it's blowing capacitors on my KTK drive.
Best of luck