XLT 4 motor

The first thing you need to do is to quit talking to Cris Fine. For one thing, his "XLT" motors are Feigao motors. As far as I've seen, the 8XL is probably the single motor that has the most applications in 1/8 scale conversions. They have plenty of torque and are not that hard to keep running cool.

My only other advise would be to go with the plain smooth can motor and use an RC Monster heatsink/motor clamp. I think you'll get better cooling and you won't have to worry about the motor coming apart. If drilled and tapped, the RC Monster sink also affords a good way to mount a fan over your motor.