Correct way to level 2014 Cummins 2500?

[Klaus96]

Update: Went with the Rancho level kit the shop/dealer installs for now. Gave me quite a discount installed so couldn't refuse. I had them install Rancho rear shocks as well for the hell of it. The kit consisted of leveling coils (no spacers), shocks and sway bar drop brackets. I had them check on the track bar during the install and they said it's not needed yet so I'm waiting on that.
The shocks are the RS9000XL ride adjustable. They are set in the middle for now. Truck rides really well and seems very stable. Happy so far.

Thanks all for the input, informative as usual!