No there is no kit. DJM used to make one but it required them machining your steering knuckles, bigger wheels and $$$$. They stopped making it a few years ago. The only way is via the torsion bars and blocks or lowering leafs. I went with blocks.
You need to check what axle you have. Durangos are built with two different size axles. 3" and 3 1/2. It does not matter if it is 2wd, 4x4 or R/T. I used a steel lowering block kit by DJM. It was the 1" steel block kit for the Dakota R/T. The Dak R/T has the heavy duty axle which is 3 1/2" dia. The 3 1/2 has a 12 bolt octagon shaped differential cover. The 3" has a 10 bolt cover. Or measure the distance between the U-bolts. The 3 1/2" inch U-bolts are also a bit larger in diameter so the shock plate holes need to be enlarged a bit. 3 1/2" block kits are tough to find. I don't have the part number with me I got it through stylinconcepts.com. They are cheaper than straight from DJM. I did not cut the rear bump stops. The fronts have to be cut. I could tell the front suspension was softer when I cranked down on the torsion bars. Bumps were less jarring. Like I've said, I have Hotchkis Sway bars and Bilstein shocks that I believe help a lot with the front end. I admit I think 2" would be perfect. 3" is getting into the really low range. I was conservative with the 1" and I did not want to have to change out my Bilstein front shocks. I seen a few posts from people that did 3” and cannot get it aligned and have very floaty uncontrolled rides.
I have an R/T and have lowered it 2 inches with a perfect ride. I have Hothkis whiched helped but I could only go about 1 1/2 inch in the front without floating untill I figured out the trick. I will probably sell kits through GS Motorsports or SoCal if there is enough demand. The trick is Coil Overs.