If you aren't worried about towing, than a Diesel probably isn't worth the money IMHO. I don't like Dodge's or GMs. I've had bad experiences with both. Dodge's do tend to have torque converter issues, but if you are getting a Diesel, it's mainly to get that extra towing edge, so what's the point of having an automatic. That's totally counter productive.
Honestly I think you are better off getting a 3/4 ton Ford with a gas engine, with a Triton V8 or V10. If you aren't towing a lot of weight, or towing often, the auto is fine. The diesel is going to cost more money in maintenance, and the fuel savings is negligible in comparison. If you have your heart set on a diesel, save up the extra cash to get the Ford.
Kurt
Just wandered into this one, but this is pretty much spot-on for what I was going to recommend. Here's my feedback (got a lot to say on this one, so hang on):
1) Had a 98 24v cummins dually 4x4 in AK. Loved it, drove it up here in AK. Bulletproof truck (had the manual), got great mileage, would pull a barn down. Realized I wasn't saving as much as I thought in total operating cost because fuel filter changes, higher cost oil changes, etc. Still loved my cummins though.
2) My dad has driven cummins diesels since they were first introduced in the early 90s. Still anecdotal, but he's pulled HUGE loads alongside friends using Ford PowerStrokes of various vintages. Lower CI Dodges always outperformed (and were more reliable than) the Fords. (As an aside, I don't know of many people who routinely use their diesels for heavy hauling that drive Chevies).
3) Fast-forward to 2003-I needed a new truck, was dead-set on buying a new Dodge diesel. Sat down and did a total cost of ownership calculation, figuring increased purchase price of a diesel engine over gas, fuel economy savings, increased maintenance cost, and (at that time) fuel cost savings, as diesel was cheaper than gas then. Figured I'd need to drive my truck over 110k miles to reach the break-even point over a gas engine. Wound up not buying any truck for a while, but during that time, a few related and noteworthy things happened:
a) Diesel fuel changed: Current motor fuel is 15 ppm sulfur content, mandated by clean air act effective 2007. Previously was 2000 ppm. Changes in refining have driven the cost of diesel to significantly higher than gasoline (where it will stay for the foreseeable future).
b) Changes in chemical properties of the new diesel result in a 10% reduction in energy produced from it's combustion. In other words, it now takes approx 10% more fuel to create the same amount of energy. So your mileage went down. Manufacturers are also having issues with the design changes to the engines built to run the new diesel. (not a lot of science out yet on the impacts of the new diesel in older diesel engines, but there's got to be some impact, most likely in increased engine wear).
So, point 3 winds up with some big strikes in my book AGAINST the diesel engine.
In 2005 I needed a new tow rig to replace my 3/4t Suburban. I pull a 4-place enclosed snowmachine trailer that doubles for my car hauler. Didn't like the chebbie, but bought it when I did because the price was right. Went shopping for an Excursion. Wound up finding a heck of a deal on a V10 gas model, but really wanted a diesel, cuz I really liked diesels, they can pull more, their more manly...But not manly enough to make me pony up $6k more for the same truck. Bought the gas. Since that time I've put about 60k miles on my Excursion, including one roundtrip from Seattle to Billings, MT for a Christmas snowmachine vacation, 3 one-way trips on the Alaska Highway from Seattle to Anchorage (two hauling my trailer, the last one with my 67, my compressor, toolbox, blast cabinet, and jam-packed full of mustang parts, well over my 10k gvw rating on my trailer axles). Verdict: This thing pulls like a champ. Yeah, I only get 9-11 mpg towing, but I don't drive like a grandma either. Without a trailer, I get 13 around town, 16-17 on pure highway. Oh, yeah, and gas engines work waaayyy better in the cold than diesels. If you want more detailed proof/info, PM me.
The last few model years, Dodge hasn't built as good of truck as what they were building 10 years ago, IMHO. A friend with a construction company owns a couple, and he isn't that happy with them, especially when he compares them to the ones he owned 10 years ago. Fit and finish is poor. Tranny and front end problems are common.
I've never been a fan of the PowerStroke either, in either configuration. Ford seemed to be constantly tuning the crap out of their bigger-cube V8 to try to compete with Cummins' smaller displacement I6, and they seemed to fail a lot because of it.
I'm sure I opened a blast furnace worth of flaming. but I say it from the perspective of a former die-hard Cummins guy. My advice, based up by some fact and experience--buy a V10 gas (I suggest the Ford). It'll haul your sled deck easily, you'll have a lower total cost of ownership (purchase price, fuel bills, maintenance expense), and you'll have what has been a reliable drivetrain/truck for me.
My two dollars worth.
and all it's needed is maintenance, a tranny, and a rebuilt injection pump. Less than $8,000 in maintenance ain't bad for 2.5 million miles! 
