The best thing I've seen for mill motorisation is a worm drive motor. No need for pulley wheels, belts etc that take up space and can be finger traps.
There's a great thread here (
http://aussiehomebrewer.com/topic/44766-mill-motors/ - I put a space at the beginning cause this forum won't let me put links in) but basically a home brewer called this shop asking about motors, the retailer didn't get a phone number, so went on the Aussie forum asking lots of questions about torque requirements, speed, coupling etc. he sourced a fit-for-purpose motor, and packaged it up. He's struggled to meet demand ever since.
I'm surprised MoreBeer or Northern Brewer haven't done the same thing yet.
While I don't think it would be worth ordering from Aust, contact a motor place nearby and see if the can get something like this ... By all reports it will work a treat.
This next link (again, with spaces so it will post) shows the unit they've put together.
http://www.motiondynamics.com.au/home-b ... oller.html[moderator edit: links are ok here. Look at the top of the edit box and there's a URL button for you to embed urls. -BDawg]