It was actually Trex's fat bike produced for you.why 500W? My 250W fat bike has all that, hydraulic brakes, thumb throttle, except for the 500W label.
BTW, you won't find a better motor for fat bikes than the Bafang G06. My fat bike has that too.
http://wooshbikes.co.uk/?rio-fb
I wonder what Trex would run his at ?I run my fat bike at 36V 17A