I think 6.8 SPC is the better hunting round but ease of finding a barrel and bolt is important.
A 6.8 bolt is easy to find. Several site sponsors have either bolts or complete bcg's. But I agree that finding an 18.6" 6.8 barrel was a b!t@#. Sure I could get one made but I didn't want a lot of money into a barrel for a not so popular caliber.
Ended up finding an 18.6" six eight barrel for an ACR on the EE. Guy claimed he only fired 50 rounds and by the look of it I believe him.
Finding the oddball stuff requires a lot of patience. Selling it again requires even more...