I used Dewalts on 36v for a version of one of my robots (Heavyweight) so they can handle it,

S28 or LEM130? Dont confuse speed for power, Storm has more kinetic energy than Sewer Snake, SS bounces alot more than storm as well, there both good robots but its not about power in the motors its about the traction in the drive, Ive seen storm been out pushed by Terrorhurtz which has 24v Bosches
The best value motor in my opinion is the 24v Bosch GPA,

Example, Tanto V3 had eteks on 5:1 and it was slow top speed but plenty of torque literally nothing could out push it, Tanto v4 has Eteks on 3:1 ratio, its much quicker and the gearbox has more torque however its had less pushing power, i got the speed i wanted but lost the power that has in the past beaten Tornado