I don't see how "reach" is important, because your the cockpit length, that is the reach from the saddle tip to the bars, can vary so widely, that this arbitrary number really doesn't do anything except allow you to compare bikes from the same brand.

So, your saddle position will be related to your your STA, crank length, body proportion and fitness. And then your saddle tip to bars will be related to how stretched out or upright you want to be. Now, how can "reach" be important? when there are so many variables affecting your final formula?

1. Adjust saddle position
2. buy a bunch of cheap stems in different lengths and use what feels good
3. sell the stems you didn't like.

that's all there is to it.