You can get "Emiko's Big Hole" mandrels from ArrowSprings. They are nice because they are pretty lightweight. I think it is easiest to make the band with a few wraps of stringer and then build up the top afterwards, like Kathryn Wardills demo at the 2005 Gathering in Louisville. You have to flatten the band a bit, and make sure to not make it too thick or else you won't be able to close your fingers--- well, at least not if you have short lil' stubby fingers like mine!!
Sara