I don't think this is going to be any faster than a stock tamiya rtr. Tell me how a 100 watt brushed motor = "a poweful brushed setup." Plain and simple 100 watts is 100 hundred watts, so even if it has 10 times the torque of a 1000 watt brushless motor, it will have 1/100 the rpm.
Check out my custom converted 8ight:
Sub 7lb, lowest CG of any 1/8 buggy