Seriously consider a dually unless you are getting a very small truck camper.

The 48RE was introduced in 2003 (but not all 2003's had it) and it is far stronger than the earlier 47RE. I would not buy another diesel ram with the 47RE, but although the 48RE is better than the 47, I strongly recommend the 6 spd, especially up to 2003. The NV5600 is the strongest transmission ever used in a light truck of any brand; with a good clutch (I recommend South Bend clutches), it can and will take whatever abuse you throw at it.