kladue said:The 3/8" connection on a 2 stage regulator and short run of 3/8" hose (< 4') will not significantly impact the overall delivery pressure when used with a pipe manifold, remember the gas jet opening for 10" LP burners is usually only 3/32".
Using 1/2" iron pipe is the easiest and most common material available to build manifolds from. While using gas rated Teflon tape for thread sealing is acceptable practice, but liquid thread sealers do not shed fragments into your gas system where they can plug up small openings in pilot and burner orifices.
Trying to switch between NG and LP on a regular basis will involve two sets of parts to switch between fuels, burner jets, pilot orifices, automatic gas valve springs, 1/2"+ hose for NG, and 2 stage regulator and 3/8" hose for LP.
Check Lowes for a 2 stage LP regulator at a better price point
What is the benefit of a 2 stage over a single stage low pressure regulator?