Since you are stating a 690 lb tongue weight with a rated 6600 lb dry weight, I'd assume you haven't actually scaled the combination. I'd suggest you get across a scale to see what you actually have. Load the trailer for camping, if possible. I believe your 690 tongue weight is going to be more like 1000 lb. when everything is tallied.
I think the right Excursion would work but I don't know payload ratings of the vehicle. The crew cab Superduty trucks have a lot of room but your dog would have to ride in the bed to fit everyone comfortably.