I bought my 308 upper & lower separately from Aero Precision and they still matched excellently. I put a 20" Aero barrel on there and it shoots sub moa with handloads. You can build with confidence on the Aero platform IMO.
Regarding your choice for hunting, if it were me, I would also go with the 16 or 18" barrel. Most of your hog shots wouldn't be outside of 500 yards I would suspect a day the 16 should do that all day.
Best of luck to you.