After much deliberation, the Andersen Ultimate hitch will afford the best solution for our towing needs. My only decision is whether to order the original (steel) version with the Demco rails that use my Titan's puck system, or order the newer Ultimate II (aluminum) version that will attach to a new gooseneck hitch ball. The newer AUH-2 system will be lighter overall, but I believe the original AUH may make a more solid platform spreading the towing weight over a larger, more secure base. I do not believe a slider hitch will be needed as my new 5th wheel has the tapered corner edges allowing for more truck cab clearance.
Thanks for all your replies & warnings. After weighing & double ckecking, I did find my actual payload is almost 500 lbs. less than I thought. We will need to load up carefully.