[Mr V]

There is no need for multiple regulators unless you want more than one working pressure, ie one at 60psi and one at say 40psi. You need at least two gauges however one showing stored pressure which would go before the regulator and one on or after the regulator(s) to show the working pressure(s).

When the regulator is hooked up with the air supply into an outlet port air will leak out of the top around the knob. I've seen this problem more than once. Depending on the regulator it can be tricky to know which is the inlet port as they are not specifically marked inlet. Typically they have an arrow, some it is on the bottom so the inlet is on the "feather" side of the arrow. Others have it on the side of one of the ports and the inlet is 180 degrees from that port.