The OP is putting it on a vacuum pump. I don't think he needs a Magnetron, Pirani, or thermocouple. A digital gauge like this one should do. Don't forget the bracket. Rescale for INHG, and put the tiny sticker on the window. Use 2 wrenches when attaching the vacuum fitting.
What is the vacuum pump used for?
There are many different types of vacuum pumps covering many different levels of vacuum required.
Mfg and Model number?
Using PSIG may not be enough readability or correct for your application. Some vacuum pumps have ultimate ranges of around 10-3 to 10-4 Torr (or 1 micron), which is below gauge pressure, which is based on Atmospheric pressure and not Absolute pressure..
The OP may have been confused by the gauges used in refrigeration. When you evacuate a system, you want to pump it down to "28 or 29". At first glance, it's not clear that the negative side of the dial is in Inches of Mercury, not PSI.
Oh dear god. You 'mericans do make me laugh sometimes. Why use a single SI unit for pressure, when you can use both pounds per square inch, and inches of mercury to measure the same thing, combining three imperial units and a toxic metal instead?