I looked at that thing online. Yeah that rig is a beast. We had some neighbors parked next to us while going thru Kentucky last spring that had one. He really liked his. It's big a took him a few tries to get that monster into the site.
But I will make this point just to give you something to consider.
We've talked to a lot of folks the past couple of years while traveling and these big heavy 5vers and the like, they beef them up with 17" rims and bigger tires and some even get the heavier axles, springs etc. I know you have 3 axles but you also have a bunch of weight too. Something to consider.
And of course you're going to need a dually to drag this puppy.
Good luck.