[lincpimp]

First we will discuss your lipos. A 2.2ah 35c lipo can output 55amps. Even in 6s this is not enough. The 5ak 20c pack can do 100amps.

Total pack capability is what you need to look at

2.2ah 6s lipo - 22.2v x 55 amps = 1221 watts

5ah 4s lipo - 14.8v x 100 amps = 1480 watts

So the 4s is capable of more power than the 6s.

As far as the motor question, the optimum motor for any voltage is usually not that great on another. The jump from 4s to 6s is a bit much for most motors. A lower kv motor with more voltage will generally perform better than a higher kv motor on lower voltage.