Dodge diesels in the 4500 and 5500 models also use urea, like Ford and GM. The Ford F650/750 with the 6.7L Cummins I6 also uses urea injection. They might have the 6.4L V8 TD in those trucks now though.
The 4500/5500 trucks and their 4.44/4.88 axle ratios will eat more fuel, have more expensive tires to replace, and have a harsher ride. If you don't need the payload capacity or front gross axle weight rating for a huge plow, stick with the 3500 series. I'm not sure if Ford still uses the V10 gas in the 4500/5500, but for an everyday hauler it might be worth looking into if you can eat the 6-8mpg. The F350 can be had with the 6.2L V8, but if you want to stick with GM and a gas engine, the 3500 GM is hard to ignore as I find GM is the best of the big3 with ride quality.
I'm in the market and am considering a RAM 3500 dually chassis. Dodge makes the only HD truck with a manual transmission (diesel only). So it has my attention on that alone.
All gas trucks over 10K gross are de-tuned for long term reliability. As an example a GM 3500 with the 6L V8 puts out 322hp, over the 360hp of the 2500 truck with the same engine. Torque remains the same, at the same rpm, go figure that one.
I find it hard to justify the cost of a diesel from Ford or GM based on the fact that they want $12K+ for the diesel and automatic transmission option. The Dodge diesel might not have the torque numbers with the manual, but is $4K less here in Canada.
I buy trucks for the long term, so I do my homework on part costs, labour, tire cost, servicing cost, etc. Some services I can axe out as I can do those myself. For 60K miles (Canadian dollars here folks), Dodge came in first place with the diesel, last in the gas engine. GM Came in the middle for diesel, and 1st in gas engine costs. Ford came in with highest costs for the diesel and in the middle for gas engine costs. The only thing that Cummins asks is to check valve lash (I believe) at around 40K in order to be covered for the duration of the warranty, etc. I don't tow excessively and the diesel manual transmission combo with the 3.73 gears (highest available in Canada) can tow just over 13K, which is nearly 3 tons more than I really need, but it's room to grow.