I used one like the one in Post # 5. I added a water pump inlet / outlet nipple in each end of the valve (McMaster has these valves with female NPT pipe threads in each end). I installed the shut off in the heater hose just inside the engine compartment, just beyond the firewall. It is more or less "hidden" under the POA valve (Factory A/C car), down near the hood hinge and provides a nice neat, clean install. The one I used has a small "thumb lever" for the shut off as opposed to a screw that is turned with a screwdriver to turn off the water.
Thanks again to Sbvelleman..his tip helped solve a problem for which I did not have a good answer at the time.