f405

Ok so I have a Mamba F405 mk2 20x20 with a max burst of 30Amps with 4S batteries and I have 6 inch props. I also want to get the Emax ECO 2207 or the 2306 motors. Now I'm not understanding the KV and what I should go with. I've had people tell me go with 2400KV then some say 1700KV and nobody...