you can make your own - i have 8 of these:
Corny Gas QD
red kegorator Gas Line
brass threaded T
Brass threaded hose barb for T
PRV, adjustable
Pressure gauge, preferably oil filled
Gas teflon tape
worm hose clamps
all the above can be ordered on amazon
assembly:
assemble gas QD, and worm clamp a short length of gas line to that. use teflon to thread barb to T. worm clamp other end of gas line to barb. use teflon and thread on the PRV and the gauge to the brass T. use the Adjustable PRV to set your pressure.
you can test by using your regulator a specific pressure to test the PRV