Welcome! Where in canada are you?
The ford F series also changed a lot over the years. What era are you considering? Something older than 2004 would probably be best simply because they were smaller and lighter. I'm partial to 1986, but thats because I have 2 of them

(F150 and F250)
My suggestion would be a 1992-1997 2wd F150. They are light and fairly low to the ground while still being a fairly simple and tough open channel frame truck from bumper to bumper. But it really depends on what you have.
Motors needed to move 4000~6000lbs of steel brick down the road are not very cheap and there aren't many that can deliver acceptable performance. However there are some that are coming out now.
Cost is as always going to be your primary limiting factor no matter what your hopes for performance are. In theory you could utterly fill the truck with batteries and still have a decent range but cost and performance won't be very impressive.