Id suggest a look at what is popular or supported at your local track and hobby shop and make a decision from there.
Most motors available are good ,you have choice ,go with Novarossi ,Axemotorrossi ,JP,RB,Sirio,MaxPower,Orion CRF,ninja.....list goes on.
Important to look at support as mentioned above.
casterracing EX-1 Pro, SP Silver Arrow
TOP Racing Scythe, SP 17.5, SP GT Pro 2.0
TOP Racing Scythe, SP 4.5 V2, Hobbywing Xerun 120SD 2.0
TOP Racing Scythe, SP 13.5, Hobbywing Xerun 120SD 2.0