Exh brake isn't a must have but it's probably the single best mod or improvement for towing when it comes time to roll down those long grades, imo.
Kzspree, you're correct there have been a lot of improvements in power and transmissions in 10 years, but from a weight carrying capacity they're still the same axles.
Towing weight is not dependent on whether the truck has training wheels or not , for the most part. Duallies are better payload and peace of mind. Power to the wheels, and chassis is the same as a srw, basically.
At 14klbs you're not in dually required pin weights yet. Given your budget, for the trucks you're looking for, I'd look for the best deal/condition truck from 2500 up to 3500 dually and buy it. No point in overkill on the dually if you have to buy a pos to get one. If the best deal is a 3500 or dually, then that's a bonus. Not that many old diesels that aren't high miles or beat up/clapped out anymore thanks to the recession and 2008 emissions resulting in a lot less new trucks sold for several years in a row.
