You certainly don't want that thing for two reasons. One, the 3. 42 gears would be a very bad choice for anything other than interstate cruising empty. A truck with 3. 42 gears would be useless on the slow speed two lane highways with low speed limits of your area. You would be slipping the clutch on launch and unable to use anything higher than fourth gear when pulling your trailer.
Second, Dodges with manual six speeds beginning in '06 use the lousy dual mass flywheel assembly to reduce NVH (noise, vibration, and harshness) generated by the power pulses of the mighty Cummins inline six at low rpm. There are numerous and growing numbers of complaints here in TDR forums from G-56 owners who report early and repeated flywheel and clutch failures. Towing a heavy trailer everyday you would be lucky to get 50,000 miles out of a flywheel and clutch assembly on that truck.
Believe me, you will be much happier with a late model six speed automatic or a pre-'06 with NV-5600 six speed, either one with 4. 10 gears.
Edit: Besides that, that truck almost certainly arrived at your local dealer via a big auction in the DFW TX area. It went to an auction because it wouldn't sell wherever it was traded in and it might have been a repo.
Fender skirts and barbed wire striping? I wouldn't be seen test driving that POS let alone owning it.