I'm in the same boat as you. I have researched EVs till I was blue in the face. I go through phases where I am ready to pull the pin and drop thousands on motors, controller and batteries, and then a few months go by as if nothing happened. I can't speak from experience, but I think I am well versed in "EV theory." Much of what I have learned is from
DIY Electric Car Forums Site Home , a very good forum to go through. So much info it will scare you. The guys there are ridiculously helpful and even the simplest questions do not get ignored.
I could get into theory and numbers and whatnot, but I will save time with this link:
EV Calculator
Punch in your numbers and play around with it. It will give you an idea of what you need to use for the EV you require. A very impressive tool.