Well, I answered this once but got a database error.
Driveshaft disconnect, good towbar, wiring and auxiliary brakes.
You will need to find a GOOD driveshaft company to install the driveshaft disconnect. Only one I've had done was for an overdrive in a '88 type B Okanagan van. The shop made an entirely new shaft out of steel to replace the OEM aluminum one. Worked OK but didn't dampen the vibration as well.
2009 45' Magna 630 w/Cummins ISX 650 HP/1950 Lbs Ft
Charter Good Sam Lifetime Member, FMCA, SKP
RV'ing since 1957, NRA Benefactor Life, towing '05 Odyssey