RE: Which Boots...
Go try boots on.
Find the boots that best fit your feet.
I fit people and sell boots in a mountaineering and hiking shop. Taller boots do not provide more ankle support. That is a fallacy. Support comes from the lower leg muscles, last and footbeds. Higher cuffs provide abrasion protection.
I hunt, hike and porter in Vasque Zephyr's. I regularly carry loads in excess of 100 lbs. as far as 20+ miles while portering.
Your feet may stay warm in Oklahoma. Add 8,000+ft. and a temp. drop of 30-40 degrees and that could change.