A few years back I experimented with continuous turn (No Mechanical Stop) Potentiometers. For my application however, the rollover from 0-1023 was too fast for the code to work with to recognize and adjust accurately for the rollover.
These are the ones I used. I found them to be reliable, and consistent.
At that I time I had obtained them from Newark-In-One.
I can't say if they still stock them or not.
Here's a link to the data sheet.
http://www.vishay.com/product?docid=...odel%20357