You can get a 5 speed, but only on the "work truck" trim level, and only with the V-6 last time I checked. When I bought the Beast I was looking at new trucks, and asked to see a 5 speed, but they didn't even have one on the lot.
The answer to that question is, (and I know I sound like a broken record here), nobody will buy it. It was available, once upon a time, but people weren't buying enough for it to be a cost-effective option to offer.
I think Dodge offers a manual transmission in some of their V8 full size pickups. I'm pretty sure they're the only one.
the dodge cummins turbo diesel (5.9 liter) is an inline 6 and has been that way until they recently changed it to a larger displacement but I think it is still an inline 6 and it got great power.
I have heard that dodge was going with a smaller V6 configuration that was going to yield roughly 200hp and 500 ft/lbs for the 1500 ram. I would buy that over the over inflated (in my opinion) hemi.
I disagree with the "people won't buy it" arguement when it comes to the diesel. look at the 2500 and 3500 trucks. most of them are diesels especially the people that use them for hauling. I can't remember a 1500 series truck with a diesel option. I have been told that they used to offer it but I wasn't around back then.
I do however agree with that arguement for the stick shift. I personally love a stick but most do not. sticks seem to be reserved for lower end cars and sports cars alone. good luck getting one in a truck or an SUV. I had to special order a truck to get the V8 and the manual and then found out that the max torque rating for the trans was just over the factory torque rating of the motor. I was very limited in what I could do with that truck so that I didn't mess up the trans.
last year, the diesels in the smaller full size trucks were all the craze on the dodge forum. everyone wanted one because it would outpull the hemi and (with modifications) outrun it as well. all that was speculation but there were high hopes.
Be the change you wish to see in the world