Where to put your probe ...
I have an X-Monitor and I am very happy with it... Sure - the digital display washes out in VERY bright light, but it is only when it is directly in the window and on the gauge - no problems 98%+ of the time. I like the fact it flashes warnings if you exceed parameters that YOU set, and it also retains MAX values for each thing monitored.
If your truck is stock, you are not at _as_ much risk as many of those who are pushing fueling boxes, etc on their rigs, but I think an EGT Gauge is absolutely a great idea!
Now - as far as pyro mounting...
I would be VERY cautious about mounting post-turbo, as you are essentially guessing what the EGTs are prior to the turbo. Also, as been mentioned many time on these forums, the rear bank (cylinders 5&6) tend to run hotter than the front cylinders (which is why many people mount their pyros in the rear-most part of the exhaust manifold for more accurate or "worst case" readings).
I would be very curious as to how many people have actually had a probe grenade a turbo? More people than have fried a turbo as to running it too hot by guessing with a post-turbo EGT gauge.
Most TDR members run probes ahead of the turbo (pre) and there is collectively millions of miles doing this successfully. I think the biggest factor is the correct mounting of the pyro probe. If you are not confident, let someone put it in for you and pay a few bucks... I did! (Mine was installed by the dealer, purchased by my wife as X-mas present for me [now THAT is a good woman!])
The choice is ultimately up to you where you put your probe

, but I think if you probe the front of the spinner :-laf you'll be happier than probing the rear of the spinner... :--) (C'mon - that's kind funny?!?!?)