A list of compatible (tested) devices is listed on the Official Montage Download page

In general, most USB sticks work as long as they don't include Copy Protection software built-in. Copy Protection = Music Prevention. Certainly don't pay extra for something that will have to be removed. The Size drive you get will depend a lot on what you're doing with your Montage. I personally use nothing larger than 16GB. I would rather a bunch of smaller drives than one humongous drive. Smaller drives are easier to back up, and I find larger drives make one lazier about backing up. How much data do you want to lose at once? Remember it is not a matter of if a drive will fail, it's a matter of when. So I avoid 500Gb or Terrabyte drives, knowing I will probably not live long enough to fill them 🙂