[suicideneil]

I would say the 1512 1800kv motor would be a better choice for 4s lipo in a 1/8 buggy- if you upgrade to 5-6s lipo it'll be a rocket ship; the 2200kv 1515 motor on 5-6 would send the buggy into orbit, or tear it in two ( Im assuming you werent aiming for 100mph with the setup ).

If that vortex esc and motor are sensorless and the esc is rated for atleast 100amps, I see no reason why it wont work with the castle motor ( just solder on suitable motor coonectors to the wires )- castle motors are 4 pole, but I assume the vortex esc can handle those, not sure what the vortex motors are off hand..