Being an even tighter wad I used a $9 liquid filled mechanical pressure gauge & $6 needle valve from Grainger and $5 oil pressure gauge tubing kit from the auto parts. Made my own gauge holder, but could of bought one for 5 more bucks. Working great for almost two years. No lighting though.
Deezul, I tried an S-W oil pressure gauge, sender didn't last long due to the pulsations. Hope you have better luck.