What KV rating? trying to pick a motor out.

[RUSTY XL-5]

Well for most 17 yr. olds, money is always tight. I'm no exception. As it turns out, running 6s in my E-Revo will be cheaper than 4s (I'll be running the Zippy 4800 25 c's). I was looking at the castle motor (2200) and realized that I wouldn't be able to control a thing with 6s and that motor. So, what would be a good KV range for me? (I'm looking for speeds in the 45 mph range with out crazy gearing) If it helps, I've been looking at the Medusa motors.


Thanks!