I got my bearings from Buffalo also however I changed it up a little bit and went with the bearings that have two set screws to the axle for the outer bearings as I've seen the lock collars break loose or just break altogether. The lock collars are more geared towards a one direction application. Buffalo doesn't stock these but they can order them. Here's the numbers if you're interested. Hope this helps.
Outer UC-207-20 R3
Inner UC-206-17
What it lacks in ground clearance it makes up for with traction.