Kurt,
The Water temp gauge will be an effect of higher than normal temperatures. Meaning that your egts could be too high for serveral minutes before your water temp starts to climb. Then your fan clutch will engage and cool down your water temp but your EGTs will continue to climb. With the loads that you carry, similiar to mine with the Slide in and the Horse Trailer, you will really push your egts. But don't let these guys scare you with the temps. I have held my truck past the top numbers recommended on here for minutes and so far no long term effects. And the newer trucks 03+ have additional safe guards to allow for high piston temps.
I have never heard of anyone over heating the transmission, but I only have 6speeds, so I am not sure on the transmission temp guage. I just may not pay close enough attention.
So the guages will be very useful for monitoring your driving style and changing it for economy and longevity.
Also your mounting options are endless. Three guage A-pillar, or single x-monitor, or in the cubby or on the column. So don't worry about space, when you are done it will look like cockpit of a rocket!!!
---Doug