Think this would be a good lipo considering its capacity and the C rating. This lipo will deliver 6400/1000 X 20 = 128amps continuous. Its the current which is a function of both C rating and capacity, not just the C rating by itself that determines what a lipo can produce for current. The high capacity makes up for a lower C rating in this case.

As long as it fits, think this would be a good lipo.