If you get a monitor, the morons at the dealer are likely to think it's a performance box of some sort.
I am going with a Quad Commander. I had gauges on my last truck and they were nice, but I want to not lose my grab handle.
For $1000 I can get Optix Boost, EGT, Trans temp, Rail and fuel pressure (with associated goodies including a-pillar and dual gauge pod) and lose the grab handle in the process.
IIRC for $450-ish I can get a Quad Commander with all the associated goodies including the pillar mount. Not only will it monitor the 5 functions listed above, but will also retain maximums, monitor coolant temp, control many aftermarket boxes (and obviously the Quad boxes) and defuel based on parameters you set (only on boxes controlled by the Commander).
You get much more for your money, but the drawback (IMO) is that it doesn't look as cool.