What is the best year to buy a chevy 2500 with the 6.0 vortec - I currently own a 2003 chevy 2500hd 2wd with close to 240k miles on it ...

I currently own a 2003 chevy 2500hd 2wd with close to 240k miles on it (I have seen almost 20mpg hwy) . This is hands down the most dependable truck I have ever owed or heard of. I bought this truck with 163k miles on it and tow a loaded 18' enclosed trailer weekly. I have had to replace the water pump, battery, altenator, and clean the TPS twice. Regular oil changes and it runs like a top.

I am posting because I am going to be selling my F**d F-450 with the 7.3l, its more truck than I need and has been endless maintenance. I have decided to go with another 2500hd with the 6.0 vortec, I would like an 07 or newer just because of the newer body style but have heard mixed reviews on there dependability. I would be completely fine with another 2003 if more dependable.

Any thoughts on what is the best year(s) to go with. Leaning toward 2wd for the increased mpg and less maintenace, 4x4 would be nice but only find myself needing it about twice per year and that what mud chains are for