Thanks again for all your input on this subject, Clutch was right and we found it this past weekend.
We picked up a 2006 Ford Expedition with 69,000 miles on it and in excellent condition inside and out.
We had a 25+ year Ford Mechanic friend take a look at it (he spent around 3 hours looking over lots of stuff on it) and deemed it to be be worth the asking price, then the dealer took our Envoy for trade and all that came out of my pocket was enough to cover the new 5 year 70,000 additional mile extended warranty for it.
Now we can't wait for our first trip towing over spring break to Mendocino on the Northern California coast.
Thanks again, Ted