Since the question is about the AUX unit, I'll answer only that.
AUX has a new system that allows it to cycle on/off as needed. This gives great fuel effeciency (advertised .09 gph). If you really want an AUX, get this one. Mine gives .25 to .35 gph, when it works. It quit 4 months ago in Jacksonville.
The next thing you'll have to do is learn how to repair it and how to order parts. The number the AUX website gives for ordering parts has never answered my calls. I have had some success ordering thru Cummins-Atlantic, as they used to provide service. The website for AUX suggests that you can get parts thru the PACCAR dealers network, but I have yet to find one that does it.
As for service, the only authorized service I have found in the lower 48 is the Alumibunk distributer in Woodhaven, MI. They left all the screws out when replacing a part, so I won't go back there. Make sure you get a service manual at the time of sale.
The Kubota engine can be serviced at any Kubota dealer, and probably cheaper than going to a RV dealer.
And by the way, the noise and vibration rivals the truck engine, which will shame you into shutting down often. Hope all this helps.
Vernon
