I have a 48 volt Bafang bbso2 500 watt, I weight 220lb and I have not found a hill it won't pull me up in low gear on pas level 1. My battery pack is 10.4 Amps and uses
Samsung 18650 26 F cells.
That being said the 750 watt bafang would be a good choice. Plenty of reserve power, better resale...