I think its not clear how much current a rage bridge will handle. If its 40A per channel and you put both channels together to drive one motor I would assume its 80A. I used to run supernova on 4QD pro 120A controllers and they used to get very hot running bosch motors at 30V. Though supernova is 2WD, when it turns it swings around the disc ie skid steering.

I'm planning a new robot too which will be 4WD.

I think brushless is the way to go in the long run, just having a tinker currently.