Is that the factory specifications or a brand of shock, or all shock specifications. " Almost 1 inch" . Look at this way , if you choose the shock from the K2500 , 8600+ , you will get a shock with valving for higher load factor. Meaning it will have more resistance to cyclic movement as it has valving based on much higher load capacity. Whereas the the K15 Tahoe, with the K15 shock has valve geometry for the K15.
Do you have a problem with shock extension on the whoop de doos at the track or jumping school buses? How often do you get full shock extension? On the rotary frame lift?
Almost one inch, 3/4, 13/16, 31/32, 63/64 ?
If it was 2 ", or 2.25 " , then I might rethink the plan.
I believe your best choice is the quality, basic versus high end gas damping, premium brand. Rather than the shock for a heavier vehicle.
But hey it's your money get what your happy with.