Eight people? You want a one ton van. Cheap and everyone gets their space. A 12 passenger van is going to put (2) people in each row of seats. A 15 passenger you could take out the back seat for more storage and still only 2 people per seat. Everyone gets in and out much easier than folding seats down and the like with a suburban/excursion. Cheapest option for a heavy duty tow vehicle as well.
We have an E350 with the V10. Stay away from the Ford 5.4 V8, not enough motor for all that you will be dragging down the road. But lots of Chevy's available with the 6.0 gas, and fords with the V10 gas or deisel.
Most importantly, get out their as quickly as you can and enjoy your time together as a family. It does not last long.