Going to take the plunge and convert my XB8EC

Tentative list of Equipment needed:

MGM Compro 160 amp, 18 cell brushless car controller
Electric Motor Mount - RC-Monster
Flight Power EVO25 5000mah 5s 18.5V Lipoly

Which would be better for a buggy if used for primarily bashing and occasional races?

Neu 1512 1.5D/F Sensorless Brushless Motor or Neu 1515 1.5d/F Sensorless Brushless Motor? Any other more appropriate motor?

Thanks!