FYI i've got a Roady2 and wouldn't recommend it. i've had to solder the board in a couple of different places in the 2 years i've had it. granted, it does get moved around from car to work a bunch, but the things i've had to solder aren't related to the wear areas in that respect.
if you do go that route though, all of the XM radios i've owned (could be different for the newer portable units) use a 1 amp 12V source which should be readily available at radio shack.
