Autometer are the best gauges you can buy, Electronic are easy to install and the cleanest fitting units you can use
Start with a tachometer, oil pressure, oil temperature, NOS pressure (good if you are running a bottle warmer), coolant temperature, voltage and if you want you can also have a adjustble speedometer that is electronically adjustable to suit diff ratio swaps or tyre and rim changes in a few minutes
You can buy what ever you want to suit your car style wise check out the autometer site and find a style that suits your taste the best good luck with your car