How often will you look at a gauge?
I have the Factory Rally Cluster, and I rarely look at the gauges. If my engine went down, I wouldn't know it till it was down, even if I had 4" gauge up on the dashpad.
The only gauges I check regularly are
1) the Speedometer; 25 years and not one speeding ticket in this car,
even tho it could cruise at 120 in double overdrive., I mean that's how fast the guy in the Corvette, I was following, was going....... But man the wind is loud!
and I check the ammeter after every 7000 rpm blast, which is 65.7 mph in First-over, just to make sure the belt is still on.
Oil pressure? well, the gauge is down by the gas gauge somewhere, and in the dark. At my age, if I took my eyes off the road to read the tiny graduations, who knows what direction I'd be going after I looked up, and I still gotta refocus!
So I vote light, but it better be a good one. and if I decided to get one, I'd install it on the tach which is up on the dashpad, where my overdrive/splitter light, and hill-holder lights are.