My son recently bought a used Denali to use on trips with the whole family (new baby+2 dogs).
It's pretty plush inside, full leather, captains chairs in second row etc. Got it off an ex-fire captain so it is super clean. 6.3L should be able to tow anything he can throw at it and it's four wheel drive too. Rides nicer than his Ram 1500 crew cab did too. It's got those magnetic shocks on it I believe.
He's in the process of de-chroming it so there's less bling.