There was an extremely relevant PRB entry just a few days back:
Here.
If you haven't already, go through his other articles on statistics, factory ammo, etc.
Your 26" 1:8 twist will easily stabilize a Berger 153.5 LRHT at your elevation in Utah, and unless you're planning on travelling to the coast to shoot a Pro series match at sea level, would be worthy of consideration. Be careful about any stability calcualtor that assumes Sea Level - you aren't. I know AB Quantum used to assume that on the first screen, but updated as soon as you got into your solution and gave it your altitude.
In addition to agreeing with the AB custom curve extremely well in my experience, the 153.5 will give you a much more forgiving wind bracket on target in a Western style match.
The downsides are recoil (you're already tolerating 6.5 Creedmoor, this will be just a pinch more) and cost. Factory Berger loaded 153.5 is around $2.30/rd and the high end loadings that I linked to above are closer to $3.00/rd. That said, if you're not going to be reloading, then I would go for something like Eagle Eye and not look back. The factory Berger loaded ammo can be good, but some lots are just average - they're not that consistent in my experience. Sell the brass when you're done.
If you end up liking the 153.5 and still want to shoot 6.5 Creedmoor after shooting out this barrel and are tempted by those coastal matches, go for a slightly faster twist for your next barrel. It's not hard to get a 1:7.5 or even a 1:7 twist with a little waiting.
