Hello Cheryl,
Here is a link to Rio Grande for a dual stage regulator for Oxygen tank:
I am not sure what type of propane tank you are using, but here are some links to Rio Grande for some propane regulators:
(I believe this is the one I recently got to replace my older version propane (non-gauge) regulator for the small disposable propane tanks
you can always call the wonderful tech support @RioGrande and they can help you find everything you need for your complete setup…like check valves, backflash arrestors, leak detection solution, etc…
Best Regards,
Julie