Which truck for my custom straight truck + trailer (not for hire)

Hi All,

First-time poster here, and apologies for the long post. Been lurking and soaking up as much as I can and at this point feel compelled to ask advice more tailored to my specific situation.

TL;DR
The short version is I'm looking for the best (in luxury/comfort/easy driving) crew cab medium duty+ truck to put a 12'+ body on while carrying a payload of 12K lbs. and towing a 18K lbs. trailer. Ideally it would be single axle 4x4 to be able to do some light off-roading, but that is bonus not requirement.

Full Story

My Work
I work in film production and am not a professional truck driver, but find myself now in the situation of needing to get a CDL and buy a truck for my own private use. I have some professional shops involved consulting on this, but am hoping to get some community advice as a bit of check-and-balance to that (from people not trying to sell me something ).

Current Setup
I currently have a 2020 Ram 3500 diesel with a Snugtop that I load up my film gear in, and I tow a 38' 12K lbs. travel trailer with me. This allows me to take my family with me on location rather than spend so much time apart. It also avoids so many flights and hotels, which got really old for all of us. Work takes us all over USA and Canada. Once we get where we're going, I unhitch to leave family at basecamp, and I take the truck to the set. A big bonus is that the Ram 3500 is so nice inside and relatively easy to drive that my wife and kids love it, it's super comfortable for our long cross-country trips, and it's a great civilian vehicle for going to Costco or whatever once we get there.

New Requirements
Recently I decided to get more equipment. This requires more space (~12' body will accommodate), more payload (~10-12K lbs. of equipment), and a liftgate. The truck needs to be a crew cab so I can take my family with me, handle that body and payload, while still towing the trailer. I'm also hoping to upgrade to a different trailer, which weights more (~18K lbs.). All of this while trying to hold onto as much civilian-pampering luxury and easy driving as possible for me and my soft family ).

New Truck Solution?
At first I was hoping to do this with a custom Ram 5500 Crew chassis cab 4x4 with super singles (so I could do some mild off-roading for remote shoots), but the numbers don't add up capability-wise. My truck builder has suggested we do a custom order Freightliner M2 Crew Cab 4x4 single axle (maintain some off-road capability). Seems to handle the numbers fine. My hesitation has mainly been how old that platform seems to be. I look at things like the Cascadia, new Volvos and Kenworths, and they are much more updated and modern. I've also heard some people complain about their M2 being rough and noisy compared to Cascadia.

My Priorities
Sufficient payload/towing capability, comfort/luxury during long trips, easy drivability around town (in that order). Of course reliability/maintenance matter, but this will be a low miles (~30K miles/year) vehicle. Fuel economy is a low priority. Cost is also not so much an issue, as this is a long-term investment.​

This is a huge investment, as the upfitting and body building will cost just as much as the truck, so I really need to get this choice right. I would greatly appreciate any and all advice and opinions, whether it's reassuring me that's a good choice, or suggesting I look at something else.

 

Is there a crew cab Cascadia? Or an after-market crew cab mod?