"Q: What is the difference between KONI STR.T (orange) and KONI Sport?
A: First of all there is a difference in basic shock design: KONI Sport is adjustable, Koni STR.T is not. A second difference can be found in the valving: where KONI Sport is developed to provide an overall sportier performance, KONI STR.T is best described as semi-sporty: improving the road handling to a considerably sportier level than standard (also suitable for lowering), with an overall comfortable feel."
Basically, Koni Sports you can adjust he compression/rebound with the knob [usually 4 step adjustment]. Valving refers to the internals of the shock absorber, in layman terms valving dictates how shocks react the abnormalities [travel].
Don't forget even though 2" may not sound like much to you or myself, for the manufacturers 2" drop is quite significant, just check out H&R, Bilstein and Eibach, lots of their kits made for 'lowering' only go down to 1.25" or so which the 2"+ lowering needing completely different product.
Check this out ---> http://www.koni.com/car-racing/products/sport-tuning/
SRT.T Shocks matched with H&R Springs that lower it by "up to 40 mm with H&R springs" ;)