I have spinal stenos in my lower back to the point where I receive epidural nerve bock procedures every 4 month just to continue working and functioning at a some what normal level. I ride an 07 rkc ,I have accumulated 51000 mi since new. The seat is a hd double saddle pillow seat with rider hd pillow back rest pad and the tall pad bracket, it comes about half way up my back just below the shoulder blades. between the height of the back of the seat and the backrest which conforms to my back near perfect I can ride the distance of my fuel with nothing more than a sore butt that needs stretching like every one else, I ride almost every sunday and every other chance I get, even rode to key west 3200 mi in ten days. When my back is really acting up the seat is one of the most comfortable places for my back. It's all about support in the right place. I'm 5'10 and about 135. when I bought the seat it cost approx. three bills, one of the most inexpensive harley sells.
Forgot to mention, I changed the handle bars to the largest set backs I could get with out having to change cables approx. 2 to3 inches. hd's don't have the part number off hand but if your interested I'll check my paper work.