Man, When you connect two batteries (ex:6s) in Series (Positive with Positive) it will double the voltage (ex:12s). When you connect in Parallel (Positive and Negative) it will give the double of Mah.
Vesc
Vesc is a ESC made by Vedder that is the better one for eSK8, It have some features that other don’t have, I think the most important is the BLDC tool, that you can ajust the configuration of your ESC. It is a bit more expensive, but it’s better. Vesc has Regenerative Breaks, Current Control, Voltage Cut off, and a lot of other features, like the UART port that, with an arduino, you can read the Data of your motor.
About the trucks
I really don’t know, you need to calculate it your self, with the motor mounts you wanna use, and a lot of Trucks have curves, It can be a problem, mine have this problem so I sanded to fit. But let’s make a simple calculation, Two Motor that have 55mm lenght, so it’s 110mm, just the motor, plus the Motor Mount, something between 2mm and 6mm, and plus the Motor Pulleys. You could Make a dual drive but in differents trucks, one motor on the front, one motor on the back.
But if you are Light, I think a Single motor would probably work.
I don’t think Quanum is a good remote
Buy GT2B and 3d print BadWolf Enclousure, of Buffalo, you decide, a lot of people don’t like Quanum, but you do what you want. I bought Alien Power Remote, everybody says it is good.
AND AGAIN, READ MORE, I’M NOT A EXPERT