I agree with Bama Rambler, if your regulator is working OK I wouldn't replace it.
That being said, I bought a Watts model H560 adjustable regulator this summer. I have it set for 45PSI with the hot and cold spigots turned on full at the outside shower.
It has much more flow than the old fixed regulator I had.
I found it on e-bay for about $20.00.
2007 Rockwood 8315SS Sold 11/19
2014 Silverado 2500HD 6.0L Sold 11/19
Back on the road 10/20
2010 Born Free 22RSK