I don't know that black Bear dolly looks a bit clunky to me. Not enough mass for a proper ride on dolly, but too much money for something that has so many joints.
I dont know what you will be doing.. the gimbals are cool right now, but in the end they are likely a fad. Steady cams have been working for years, are more flexible and easier on the operator. Try cramming a red epic, cinema lens, batteries, matte box on one of those hand held gimbals and watch the motors die. Coupled with a BMPCC though, might be a great match.
Now if it were me, Id invest in a kessler crane gear... cine slider, pocket job, kessler tripod etc. And a good fluid head to match.
I was on a shoot, AC'ing for a red epic two weekends ago, there was some rental slider\dolly thing called a flow cam that really just sucked. When we moved over to the kessler gear, solid shots.