not local, but aircraft supply has one that i use that works like that.
you could make your own manifold with a shut off valve.
Description:
Affordable easy to use nitrogen fill adapter for filling shock absorbers
Assembly contains a special no loss air chuck valve so no pressure is lost during filling
Features a built in pressure gauge that allows the shock to be filled within 1 LB. of accuracy
The braided high pressure air line allows the gauge assembly snake around chassis components to easily access the shock shrader valve.
Critical for air shock applications
Hose length = 22"
I just bought the one off polyperformance.
i just set the regulator and plug it in .....