What gauges are people running?

What are the most useful gauges for the XP 1000? I will be installing a Belt temp gauge along with the Alba blower. I am also contemplating 2 other gauges.
1. Water temperature gauge – my riding is Glamis, Ocitillo Wells, High desert( Stoddard Wells road and Johnson Valley. Reasoning is hot weather means monitor engine temp.
2. Volt Meter gauge – reasoning for this is the threads I read on the voltage regulator failing. I will be running 2 85 watt halogen Piaa lights.

Give me some feedback on what you think are the most useful gauges to be running.