I would think the motor needed to do the work would be the first consideration and all else would follow based on motor choice. ESC and voltage being driven by the motor decision. Obviously the ESC will need to have the current capabilities to handle the motor. Water cooled could be a plus but there are some design issues involved with that. Not insurmountable, just added hassle.

Only restriction for the battery is I want to go with a LiFe. Weight is one consideration to this.

Since there will be 3 of them I was thinking something along the lines of the Cobra C-2204/58. Just to provide an example.

Budget is pretty open but I don't want to get crazy. This is a fun project and will probably be more display than actual running.