Ground is common on so you only need one wire for the sensor. All temperature sensors have two wires. Pressure sensors have 3 wires. That kit of yours allows you to watch up to 3 exhaust temps. It won't work for what you want. You can run two wires to your temp sensor if you want or buy one from say Delphi that has a weather sealed connector for both wires.
I would make sure your idea will work. I did not read anywhere that you can use the pyro provision for your trans temp

 

The kit will allow 2 exhaust temps. So im guessing with the kit for the bullydog one of the wires is power and one is the ground. So instead of grounding it outside of the truck, its just grounded at the supply? I talked to bully dog and they said they did the same thing on an 05 Cummins. He just didnt know what exactly they did. Other than they used the PCH box and a watchdog.

 

Well after much frustration i figured out my plans. I can simply use the pyro kit as a trans temp. The pyrometer will read low enough to monitor my tranny temps. So I just need to find a type k pyro with a 1/8" NPT sensor on it.

Like this: Sensor

 

Even better. I found one that you can get the sensor in type J. It has a lower heat range but will be more accurate at lower temps. The type K with the pyro kit is for 300+ degrees. But a type J would be perfect for this situation. Now I can finally sleep easy.

http://www.omega.com/pptst/TC-NPT.html

 

Just called Bully Dog and managed to get ahold of someone that knows what they are talking about. He confirmed my findings.

That a Type J Pyrometer will work with the Pyro kit. So now I just need to get everything ordered, lol.

 

Good luck dude