Could just go with the max6 you have and get a 4074 1800-2100kv motor. I ran my outcast for quite a while with a max6 and the old blx4074/2050kv motor. I was on 6S at the time, but that esc will run on 4S as well.
Or you could just dial the punch down on your max6.
I run a max6/4985-1650kv on...