Mark:
The gauges I ended up going with based upon some local friends view was the boost. I think this is a must gauge, as tells me when turbos are going. The Wideband air/fuel ratio. My friends told me this was a good one even though I don't race from the standpoint of getting a base point at which the engine is running to you can tell very quickly if something it's working right. Lastly I went with EGT, looking back only thing real nice is constantly changing so looks nice & does give engine temp so if somethings wrong you know it right away. If had over to do would probably go with the oil pressure. When I was looking at it, I don't think it requires using a different filter. I think there was an adapter plate with it. To be honest only down side to digital is black when not using & when it's real bright out a little tough to read. But with our gauges being digital, I agree w/ges regular gauges I think would look a out of date & if you look at the demo of them turning it's an eye full that's for sure.
MikeV