you will love it.
I converted my push bike a few months ago.
Retained all the push bikey bits, 21 gears etc in case I run out of battery.
I used the same brand as you. Got a 48v, 1000w motor. Using a 48v 36Ah battery goes like stink.
The controller I used allowed me cruise control and a 3 level speed control as well.
I have connected the brakes as well to instantly cut the power and allegedly to re-generate but I see little evidence of that.
Not done much on mine yet apart from speed trials. :lol
Speed level one sees about 14 - 15mph
I have seen 26.8 mph on the speedo.........
I'll get some photos up if you are interested ......................... or not if I am boring the fuck out of you...