I think I've settled on the 280 Ackley but the 6.5x284 is still in the back of my head. I haven't ordered the barrel yet but should be doing that soon.... so maybe I'll order both barrels and build 2 rifles!
I plan to also start a "rifle overhaul" thread when I start in on the project.
Good luck. My 280ai with 160s is a killer.