I am a service man in Oklahoma. I'm not sure what the rules are in VA, but you might want to start there. I know here things have to be a certain way, or we can't fill the tank. Now for my opinion...Get yourself a POL tee, and a high pressure regulator from your propane company. Unhook the regulator from the tank and install the tee. Install the two regs into the tee, run your piping to where you want it, install a shutoff valve, and your adjustable regulator and hose. Might want to put a shutoff after the regulator on the tank just In case. Personally I would run 1/2" black pipe, but depending on how far you are running the line you could prob. use 1/2" refrigeration copper. Hope this helps.
Edit: forgot to mention that the high pressure regulator is 10psi set from the factory.