I want to get some Autometer Gauges. Im getting the dual gauge cage that goes in the AC vents. Im looking at Water Temp,Oil Temp, Trans Temp, or Air/Fuel Ratio. which 2 of those are the best to get. Also, whats the difference bewtween mechanical and electrical gauges??? Which are better, and which ones are easier to install. Also does any body have pics of their dual or even triple guage cages??