Does anyone know if REGO 2 stage propane compact regulators work in the US?

http://www.rego-europe.de/1/pdf.html?pages=14&idupl=276

Perhaps they have a 2 stage regulator that fits a Westy without
having to modify the propane lines???

With the newer Marshall Brass 2 stage units you have to cut and
reterminate/flare the propane lines to make them fit.