Just a thought, if you have access to a sprayer and a compressor, you can paint it in your yard/driveway. Super easy, still have to tape off just like spraypaint, but you wont wear your thumbs out, and it wont take much. Alot cheaper too. I bought a gallon for my Sub, I coated it probably 7 times and still have enough to paint it again, and probably again. I used a quart of clear and did it 3 times. It doesnt take much, and its so much faster.
Btw, if memory served me, it took me 18 cans to do a longbed pickup, give or take a few.