Craig you will be running in a circle. For 19lbs you would need the power of about at least 4-5 KW and you canīt put that thru the OBīs because you are limited by the Flex in the OB and the Propsize.
The best chance i see is using 6 S and motors like
https://www.hobbyking.com/hobbyking/...?strSearch=h31 or
https://www.hobbyking.com/hobbyking/...arehouse_.html
take care
Axel