We had a 2001 suburban that was great for hauling my two labs plus the whole family on 1,000 mile trips. I'd hate to see what they are asking for them now. I found the Avalanche to be just as good if not better than the suburban for those same trips with dogs and family.
I think you are out of luck when it comes to mid sized SUVs. We've been looking at the Q5, RDX, and XC60 as our next purchase. The rear storage is fairly small. We used to have a traverse and it might have been big enough in the back for the kennels. I just never really liked it. A good, used Tahoe might be the best bet.
