I made a bracket and mounted it on top of the fender well. Looking back, that was actually the most difficult part of doing the conversion, but not because of inability to mount, but the tube that goes between the regulator/vaporizer and the carb that was supplied was too short, therefore limiting where I could mount it. I should have purchased a longer tube and I would not have had any problems.
As far as removing the tanks go, I have a custom bed and a mounted the tanks in such a way that they can be filled while still mounted on the truck.