i had the same problem with mine i wanted a 1/2npt pressure regulator that went upto 175psi. what i found is they are hard to find for decent prices.
so what i did was plumbed in a coupler for 175psi unregulated.
and then put in a regulator to knock it down to 150psi, you then can put another regulator to knock it down to whatever psi you need for the filters and such.
if your trying like me to utilize the 175psi 2 stage compressor the first regulator is to hold the tank pressure back at your set PSI, the 2nd regulator will drop it down to what you need to use.
i tried running just one regulator at say 125psi but it kept bleeding down until the compressor kicks on again it wouldn't bleed down cause of the pressure differential of the switch.
and if you dont want to use 2 regulators, you can just turn your pressure switch down to 150psi or 135psi. but you wont have that additional amount of air to draw from 175psi is more volume of air then 135-150psi.