need some new buyer advice on truck selection, towing

[Bug1]

I need some advice about buying a Ram turbodiesel, so hopefully I have come to the right place!

I am looking for a truck to fill an all-purpose vehicle role, it will be my primary "good" vehicle for when my beater projects arent running, it will be our camping rig (yearly backcountry camping in Nevada/Oregon desert, this is why I want the 12-valve for reliability) and it will be used to tow between 8-10K, sometimes for long distances (i.e. from Washington to California or Utah, in the summer heat). I am looking for a Ram because I have had good luck with a 1994 2500 gasser, but I need a bigger cab and a sturdier motor for towing. Since this will replace my diesel Mercedes as daily driver it has to get at least the same mileage (around 23mpg)

Here is what I think I want: an early 1998 12-valve 2500 4-door short box 4x4 with auto tranny and 3.55 gears in the rear.

I want the 3.55 gears so I can keep it at 75mph/2000rpm for fuel economy at speed. I want the short box so I can have the extended cab and still get into parking garages and other tight spots, as well as for light-duty off road travel. I dont need a big bed, I have big trucks for that stuff.

I know I get penalized in GCVW with pretty much everything I list above, so I am wondering if I need to change my wish list if I still want to be able to tow. I already assume I will need to replace the auto tranny with a beefed up aftermarket unit, get load-range E tires, etc. I would also be open to an over/under aux tranny, but I dont know how well they play with the automatic. As far as the trailer goes, I am looking at a custom-made bumper pull tandem axle for hauling my Unimog around, so it will be properly balanced as far as tongue weight and all that goes...

What do you all think? Any real-world advice is greatly appreciated.

-Zach