A gauge inside is a very nice thing to have! I know you're trying to keep it simple Matt, but you're already going to have a manifold right for your pressure switch? Running a line inside the cab to a gauge isn't that tough, and can be useful.
82 fj40, 99 uzj100, 06 gx470
05 525EXC, 01 XT225, 09 TTR125, 07 TTR90, 07 CRF50