I have the Dodge Cummins with 6 spd manual transmission and I absolutely love it. When I was looking from my truck, the Cummins diesel, manual transmission, and an 8 foot bed were my only "must haves" to seal the deal.
My friend has a very similar truck to mine with the automatic and manual gear select option, but it is not the same as the all out manual. The electronic manual gear select actually only locks out the higher gears than that which is selected. (i.e. if you have 4th gear selected, it will automatically operate between 1st to 4th gear as normal, but will not go any higher)
It's too bad you can't find one locally.
2011 Dodge Ram 2500 Cummins
2012 Starcraft Autumn Ridge 297 BHS