I share your feelings about the 'short' full size SUVs. I've always felt the Tahoe was basically a ruined suburban that only appealed to people with neurotic self-image issues that kept them from objectively acknowledging that they should have either bought a suburban or a minivan.
For the record, i have nothing against the long-wheelbase escalade. It's just a fancier suburban.
Personally, im with Failboat on this one: Used but newer conversion van. You'd have to get the longest-wheelbase with two rows of captains chairs and a rear bench to hit your seating goal, but it would be a fantastic way to get around with your family and racecar in tow. You'd probably be looking at a GM with 6.0 or 6.2 gas and a 4l80 or the newer 6spd auto. With proper fluid cooling im 100% sure it would handle the towing although i'm guessing the 'official' ratings would have you near or over the stated 'limit'.