You would be able to run any 540 motor.

I personally ran a castle cm36 5700kv since I found one used for a good price (Don't really need 4pole as that will just give you excessive torque). That gave me really good power and speed. I was always light on the throttle and was rarely ever at full throttle unless I had a lot of space (which I don't at my local park).

There are cheaper options though like a TACON motor or a hobbywing one.

If you shim up your diff's properly and adjust the slipper well you won't have diff issues. I personally shimmed up my diffs and never had issues. I also had a castle ESC that allowed me to limit torque and things too.

My advice would be to pick up a hobbywing system. It is cheap and very customizable in terms of setting. Or maybe find a cheaper castle system (sv2 or sct + 540 motor.