Purchasing a Used TB

I am looking at purchasing a 2001-2004 tb,envoy, Rainier, or bravada. Wondering if there are any years to avoid? What type of mileage can i expect? Anyone have a V-8? I tow a 18ft Lund Tournament fishing boat (aluminum boat, v-6 outboard) and am wondering if anyone has towed with about the same amount of weight behind it.

Not problem towing with the std set up, may consider a trans cooler if the area is hot or hilly where you will be going. Stay away from 2002 for sure, maybe 2004 up. MY 2002 gets 17 50/50 in mild weather, 21 at 70 highway and about 12 pulling 3500# Starcraft 18ft fishn' ski.

Ive got an 02 TB LT, and I havent had any major problems with it. I tow a 3400lbs and 3900lbs (dry) boats 330miles a few times each year over a pass, and have never had a problem. The standard 4.2L I6 will give you plenty of power to tow that 18 footer, as my boats are 21' and 22' with dual axle trailers. If you are really concerned, get an 04 EXT (7 pass) with the V8, it has more low end torque, but not much more.
The TB/Voys/Bravadas are only available with the I6 unless you get the EXT, while the Ranier comes standard with the V8 in the SWB model. I would stay away from the 02s, just because they are first year models, but I havent had any problems with mine so far (57k).
Also, if you are really worried about tranny temps, get a $50 tranny cooler from summitracing.com. I am getting ready to get one with a temp guage as well as an air lift suspension setup for my 02 before spring comes.