The Concolor (Abies concolor) sounds a lot like a Blue Spruce.
(we don't use it much here, so I looked it up in one of my books)
The one thing it will not tolerate for long is a heat wave.
The base *can* get up to 20' wide.
But like anything, it can be sparingly, yet artfully pruned to any width.
Yearly light pruning is the best way to control the width.
It's a faster grower than the Serbian.
The Serbian Spruce (Picea omorika) is a slower grower, and gets up to 25' wide at the base.
Once again, no prolonged periods of high heat.
The Concolor will be a denser tree that the Serbian.