My 2 cents on the bench vs captain's chairs debate. We have 3 kids, all in car seats, and a large dog. Road trips with 3 kids in car seats would be pretty miserable for me having them 3 across a middle bench seat. They would be messing with each other the entire time. Maybe all kids aren't like that, but my older boys are close in age and just can't help but to constantly mess with each other.
Also, I like the captain's chairs because then the dog has more space to lay down. She'd be pretty cramped just in the footwell area, but she loves sitting in the middle where she can be near all 3 kids and see the adults in the front seat. And because it gives the kid who sits in the back more room to get into the back, and more room for us to mess with his car seat and whatnot whenever necessary.
Speaking of child car seats - it sounds like you have them so make sure you see what kind of seating arrangements those older suburbans have that the tether anchors. Not all cars have tether anchors in all 3 bench seats (middle or third row) now, so you'd need to look into seeing what was available 10-15 years ago. That could have an impact on how you arrange the car seats.
