Going to take the plunge and convert my XB8EC

Ok, after researching summore:

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
Neu 1512/1.5y/F finned motor
Neu Rear endbell cover

Guys, will need some input on gearing for the buggy. Which would fit and be 'safe' for such a setup pls?

Thanks once again!