Does anyone have any experience with Kelly Controllers?
They do an 84V / 400A series motor controller for $389 which is a bargain (if in fact the controller is any good!) This is what I'm thinking of using for my CB-84V (was a CB-72V, then a CB-96V and now looking like a CB-84V :-))
They also have a brushless controller coming soon (which they say is 3 phase and 6 phase compatible) - they offer a 48V and a 72V model. Combining the 72V model with LiFe batteries on an XM2000 would be interesting...
http://www.kellycontroller.com/mot/Products.html - existing model.
http://www.kellycontroller.com/mot/Brushless-DC-Motor-Controller.html - coming soon brushless controller.