With 200kv you need 100Volts even to spin it as slow as a gas motor, are you working on a 30s ESC? If so how are you dealing with the safety aspect, 3x separate 10s pack inputs which are series connected internally within the ESC?
Hot Bodies Lightning 2 Pro carbon, Mega 22/30/2, MMM, 4s3-5Ah.
Tamiya F201 carbon, Mamba 7700, MM, 2s A123 2.3ah.
Xray XT8, 1518, MMM, 4s5Ah.
Lots of boats. fastelectrics.net