I bought mine used from a guy going to the 800. I already had a heavy tripod, one that would bring the lens up to eye level and more without raising the center column.
The guy bought a Sprinter camper van with a pop up or open up roof so he could stand in the camper with his camera and lens mounted and shoot from the van.(Yes, the van was camouflaged) So don't forget to add $150 - 500K for one of those! A complete editing suite, internet, and generator were added, of course.
Neuro might tell you if RRS is planning to offer one.
You can get a donkey for 35 bucks around here but that van is way better, I would get that instead!