im going to get the triple gauge pod for my sti but ive never owned a turbo before and i know i should get boost gauge but what others are best to have? want to make sure i get useful gauges.

Boost, EGT, and oil pressure are pretty standard for first three gauges

ive heard of having a fuel/air ratio gauge. how important is that one compared to the ones you listed?

wideband air/fuel gauges are important once tuning comes into play. for tech info NASIOC is pretty good. just read the faqs in the manifesto, ask your questions here.

boost, oil temp, oil pressure, though you have a light that will come on when you have no pressure, i think it would be better to know before you get that far that the pressure is running low.