My impression of Jump Range is that it improves the player's accuracy as he moves increasingly farther from the basket.
For example, let's say we have a center with atrocious jump range. He can effectively dunk and tip the ball in at a clip of 30% (made-up percentage), but his jump shot from 1 meter (made-up distance) has only a 10% (made up) chance of going in. If he were to pop in JR, his dunking would increase to 32%(made up), and his 1-meter jumper would go to 16% (made up), while his ability to make a 1.25 meter jump shot would begin to exist at 3% (made up).
When we get to people with higher jump range, they're probably not going to increase the distance from which they can shoot, but rather their outside shots would become more accurate.
Anyways, to the original question, I would recommend for you to have jump range to be one or two levels below jump shot. It's useless to have a good range if you can't actually shoot the ball, so go for jump shooting first.