As far as a wideband o2 goes the innovate is the best. I have the XD-16 its costly at $300 but it is by far the most accurate and fastest response time. On top of that you can fully program the colors of the LEDs as well as record strait to your laptop from the gauge with included software.

http://bp1.blogger.com/_X0qiKiqN1Tw/RpF95o...00/chart_lg.jpg

 

I also have a glowshift oil pressure gauge. Heard good reviews on their accuracy and quality. Seems good to me anyways I like it.