IMHO, it depends on the gas port size and gas system length size.... and Aero / BA is normal GP sized.
I use Tubbs 308 Flatwire recoil springs on all my Large Frame AR's
As for the buffer... that will depend on the internal OAl of the carbine receiver extension.
The Aero version is a "DPMS Pattern" and requires the use of a 2.5" 308 carbine buffer....
A "Armalite Pattern" / Vltor length carbine receiver extension ( buffer tube ) requires the use of commonly available 3.25" Ar15 carbine buffers.
IMHO, buy the heaviest buffer you can find.
2.5" DPMS pattern buffer from KAK 5.3oz
https://www.kakindustry.com/ar-15-p...idual-buffer-parts/lr308-carbine-buffer-heavy And as for a 3.25" buffer ( Armalite Pattern / Vltor length ) ... just buy a quality H# buffer.
Given your 20" barrel ( and most likely ) rifle length gas system.... using the above parts will basically give you the same buffer weight of a typical rifle length buffer system.
Remember, Large Frame AR's typically need little extra break in...so be patient if the first few dozen rounds are fussy.
I prefer heavy buffers and recoil springs... so YMMV.