I am currently choosing between Laramie with level 1 package and Rebel 12 Black Edition level 2 package.
Laramie is not a sport version, but perhaps can help you make a choice. Check the files (equipment lists) for both options.
Basically, Laramie seems to be noticeably more on-road truck (more comfy), while the Rebel is clearly off-road.
To me main differences are in lockable differential with Rebel, in my case info screen (but L Sport also has 12") and fancy features like memory mirrors, seas and pedals.
Tires are 18" vs 20" (R vs L) and Rebel has 1" lift.
What bothers me a bit is lack of vent seats in Rebel.