Powered Paddleboard

I just got my first inflatable paddleboard. I've found a few "kits" to replace the rear fin with an electric motor and they all, at first, seem great. When I try to look at closer details to compare cost to; power, speed capabilities, battery voltage and capacity, ect, well they must either think someone buying their "kit" is not intelligent enough to understand any technical specs or maybe they are ashamed to post them. I don't know.
Either way, this prospect got me into youtube videos and I saw a kid who used a bl motor sss 56114/700kv / 5y on his inflatable paddleboard.
It seems this motor is sourced from the e-boat scene.
I'm still in idea stages here but if anyone could give me some direction or advice I'd really appreciate it.
My specs are;
I will primarily ride in the river so I'll need a prop with a cage. It should be as low profile as possible. I don't want to hit rocks. My 9in rear fin is already too deep.
Inflatable Paddleboard is 16 lbs and is 10ft long / 32in wide / 6in tall
I weigh 145 lbs.
I don't think a build would be worth it for anything less that 5mph so that's got to be my minimum speed to try and make this happen. I'd love 10mph or more.
I've already got a couple extra 10s batteries from a hoverboard and an e-skateboard I'd like to use. One is 158wh and the other is 270wh.
I imagine I'll need a small waterproof wireless controller, an esc, a motor, and a prop with a cage surround. (Does the motor with a caged prop have a name in boating)?
I understand I'll need to create a waterproof box to house my batteries and controller.
Am I missing anything?
Any help, advice or even "virtual builds" you guy can send my way would be awesome.
Thanks in advance.
RogueSumo