I think you'd be much better off in the Suburban than the truck. The burb is already large enough to sleep in, and you have the back seat for extra storage. You mentioned possibly pulling a camper, or adding a slide in camper, to the truck, there's no way I'd recommended that.
The camper adds lots of weight & height, not good in winds or traveling through areas with damage (low trees & wires). Pulling a camper would be a huge PITA. It will kill your gas mileage, make it impossible to turn around when you get to areas with damage & the road is blocked. Leaving it somewhere, while you go chase during the day, and then returning to pick it up later isn't practical. I've started my chase day in Nebraska and ended up in Oklahoma by the end of the day. If you're worried about gas mileage, you can't possibly back track to pick up a camper at the end of each chase.
I'd work on getting your transmission rebuilt, in the burb, and make it your chase vehicle. Just my opinions. As long as you're safe & have fun, do what you want! Good luck whatever way you decide to go!