The 2006 5.9 cummins is bullet proof and is the last model before all the emissions [censored], you got a great truck that will last you at least 400,000 miles. I have one in my back pasture that I use to pull down buildings, bridges, or what ever you need.
Only issue you will have is the air conditioner. They go out. So mark my word, find you a good air conditioning repair man.

Yes, I actually owned a 2006 hemi a while back. I tore the dash apart, replaced all the blend doors, motors, etc. Not fun. This one has a brand new blower motor in it already. Even though I bought it from a dealership, I actually got to talk to the previous owner. His name was still on the Bluetooth pairing history. Got lots of good info from him.