I think I want to have the OP's garage and toys :) That's quite and arsenal you list.
I can't be a lot of help on the truck but as a guy with a wife and 4 kids can tell you having a second vehicle is REALLY nice. There are countless times when different groups of the family want to go to different places. I'd be looking at a dually 350/3500 for the main hauler and plan on bringing the van or whatever else as a second vehicle. Ideally, the dually would have a front bench seat so you could pack in all 6 in a pinch, if needed.
