Only a couple of types of regulators, single stage & dual stage.
Single is used mostly on BBQs and other fixed flow items. With multi appliances attached, yours should be a dual stage. Take the old one with you to a RV or propane supply store explain what it's for , I'm sure you'll get what you need.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.