Since you live in the warm South, I would NOT run a 10W-30 or 5W-40 in that rig. In Texarkana, it won't get cold enough to consider these thinner oils.
Run any quality 15W-40 HDEO and quality OEM, Fleetguard, Donaldson, or Wix filters concerning oil, fuel and air. Do these things and that wonderful truck will run a long, long time.
Please follow the maintenance schedule as outlined in the owner's manual, or the OLM, which ever comes first.
You may wish to have two or three OCI's oil analyzed to get a feel of its effectiveness and the engine's performance. Post those here and let the experts comment on the results.
Enjoy that BIG and LONG setup!