Lifting 2011 2500
Is it a 4x4? I'll assume it is. Whats is the stock gear ratio?, probably a 3.73 or 4.10. Is it a Hemi or diesel? The disels weigh almost 1,000# more on the front and typically the better kits have different springs to compensate for the extra weight. What are you more concerned with, offroad ability, or looks and maintaining the capacity for hualing payload?
Pics of my 2011 2500 4x4 are here,
http://www.ramforumz.com/showthread.php?t=98599&page=5 , read through this thread and you will get very good information about the various lifts (there are a lot) and tires for these trucks.
The first thing you need to know (and you may already) is most of the information on the forums is for a 1500, which does not translate for the 2500 models. The 2500 trucks already have a few more inches of lift than the 1500s, and the lifts are for different systems. I actually have a more detailed step by step install of my Rough Country lift if you go that route.
I do like a little rake, and don't like the Baja high front look. Most of our trucks are between 2" and 2 1/2" taller in the rear stock, but load them up with just 1000# or so and they sit level, or after some miles they loose a bit of that rake. I haul a trailer and typically have about 1500# (tongue weight included) in back when I'm offroad, so I wanted a little rake. My Rough Country lifted the front 4.5" (they called it a 5" lift) and 4" in back. It's perfect for me, as unloaded it's now about 1.5" higher in back, and when I hook up my trailer and load her like usual, she sits level to 1" lower in back. Most lift kits over 3" will include a lift block for the rear and most lifts will lift the rear 2" less than what they lift the front (to level it). Most of the 3" or less lifts only lift the front, with either a spacer to add preload on the front springs, or new longer springs. Most prefer new longer springs over compresing the stock ones, and progressive springs (more expensive) are typically prefered over single rate. The 3" lifts by Kore, Carli, and others often come with minipacks rear springs as well to replace the overload spring on the rear, they usually don't lift the rear much if any, but make them a bit more compliant for offroad. The one thing I didn't like about these systems is that they do not relocate the track bar, and after calling them, they really recommend an adjustable track bar to relocate the axle, which then starts making these kits really expensive for just what really turns out to be a 2.5" front only lift. I say if your going to lift it, then lift it and stick with around a 6" lift. The FabTech kit is a great kit, but they tend to be front high kits, I choose the other end of the spectrum with the R/C 5" kit which levels the least. Most of the otheres are between them, shooting for a level ride. I prefer a short arm kit, because I can go back to stock if needed, a long arm kit usually requires removal of mounts. On a new truck, you may have warranty issues, so being able to return to stock was better for me.
Other things to consider. Bigger rims give less sidewall height and are damaged easier in offroad conditions and can't be aired down as much if you get into something nasty, they can also increase the costs of the tires a lot.
You will need to reprogram your truck for bigger tires for your speedometer, the mileage computer and shifting, some have issues with the ABS systems with bigger tires as well. Again, this could cause warranty issues. You will need an alignment with any of these routes.
