if new is out of the question because of price, you'll likely be disappointed if you limit your search to 2000 and 2001 model years. they can be just as pricey as a new car.
as for suggestions, might i offer the chevy/gmc suburban. aside from the ford excursion (or was that the expedition, i can't remember, which ever is the biggest one), there isn't a larger vehicle out there. seats eight, plenty of room in the back for cargo (even with third seat in, i packed a 29 gallon fish tank and a 30 gallon cage for my anole from phoenix to indy with lots of room left over for the rest of the animal gear).
i just got a '96 and absolutely love it. won't be buying anything else again.
i've heard the dodges can be problematic, but never had any experience with them personally. have only heard anecdotal evidence.
not partial to the ford SUVs at all so i don't know a thing about them. however, i know a guy who is looking to upgrade for space reasons from his explorer. so depending on the number of children and gear that usually accompanies them (and don't forget to think of the future when they'll likely have more) and yours and your wife's gear, the explorer might not be a best choice for the long run.