Yes they certainly exist.
Couple thoughts.
1. $40k is totally doable and a Ext cab short bed is much better than long bed crew for turning. Addl solid axle trucks like ford or dodge turn tighter then ifs GM trucks.
2. Ditto on the generator. Get a Honda 2000 and figure out how to store it/ lock it up. More versatile than a built in and propane generators really suck down the propane. Guessing gasoline easier to refill than propane out in the bush.
3. Unless you're really needing the space, stay away from the heavy slide out units like Arctic Fox, Eagle Cap etc. for off road considerations. they will have the water / waste capacity you're looking for but there's other ways to carry extra water.
but if you want one of those in a ready to roll rig, I' may be parting ways with the truck in my sig and the camper could go with it......all I'd add for an expedition would be heavier wheels and tires.
