I just came across this product on the stagecraft mailing list. (As I am finally starting to catch back up from all of the end of year trappings.) The link to a site that sells these tape rollers is:
http://www.taperoller.com/ I have to say though, that while they look very handy, I would hesitate at the price tag. Especially when they look like they could be fairly easily made with shop labor and mostly parts around many scene shops.