If it were my Thru-Hike, I'd be doing it in a PV kilt. The best all-around mix of options. Light
Machine washable
Easy to adjust it down in size with the velcro
Drys quickly
Without buckles and straps, nothing to rub under your pack belt (if your pack has a belt)
Will look great without a lot of effort

The other option if your heart is set on wool, is to buy a lighter wool fabric (10 oz.) and make an X_Kilt.