I'm playing to boost soon with the GM S/C Kit. Prolly will also add headers, and a few other bolt ons. I'm going with a boost, oil pressure and not sure what the third gauge will be. I was thinking a wideband gauge. I don't plan on doing any tuning beside the GM Re flash. Do I even need a wideband gauge/sensor? Thanks. Any help is appreciated.
First off, b4 someone else flames you, you have a HEADER, not headers.
Now that that is out of the way, you don't necessarily need a wideband if you are going to have the reflash done and don't plan on doing any other type of tuning and/or upgrades. However it is a nice gauge to have either way. If I had to fill up a gauge pod, and already had a boost and oil gauge as you mentioned, I would go with a wideband next.

2010 Subaru Impreza WRX Limited
1999 Cavalier Z24 Supercharged
1999 Grand AM SE (Beater Car)
1997 GMC Sierra
2007 Honda CBR 600RR
2005 Honda TRX450R

Yes, I have a header my mistake LoL . Thanks for the info.
boost , fuel pressure , and wideband