Apparently you have not seen any of the more recent training films.
In any case, the obvious answers are things like:
quality 1-4
maybe a spectre although I still hate the mount
aimpoint, although on a .308 you might as well get some magnification to take advantage of the extra range
My preference for this situation, which naturally I regard as highly probable, is as follows:
US Optics 2.5-10 or similar
offset T1
BUIS and hell, if it's for the zombie apocalypse, maybe a set of dueck offset irons too.
This way, you have LOTS of range. Lots of target ID ability. Great up close potential through the T1. Years of virtually indestructible performance from the micro. In the event your glass gets wrecked, you have the T1 so no instant panic. If your T1 gets wrecked you still have an offset close range option.
Irons as a primary sighting system are dead. They are slower during the day, WAY slower at night, harder to shoot on the move, harder to shoot moving targets with, require vastly more practise to retain similar skill levels...
The ONLY time I've ever had a situation come up where I found irons preferable was in heavy, heavy rain, at night. The rain was so bad the lens was constantly obscured and the intermittent light made it difficult to make anything out. On the other hand, shooting accurately in the dark at even 25m with irons is so hard that it wouldn't have been much better. The best option would have been tritiums, I guess, but I have never used them on a rifle and don't know if there are issues with them as well.
As it was I had to constantly wipe the lens with my thumb. I got about two or three seconds between the lens being completely obscured. But again I could not have done much better with just irons, either.