I have yet to see an actual complete A2 stock kit for 308, but you can buy the Aero Precision 308 A2 buffer tube set up and then source an A2 stock else where.
That being said, the A2’s have been harder to come by in recent years.
There is this option.
https://truenortharms.com/ar15_default_store_view/milsurp-a2-buttstock-partial-kit-black-or-grey.html