Be careful with that. To me, it really looks like you're quoting weights for VLTOR A5 buffers, and those WILL NOT WORK in a 308 setup, at all.
Armalite EA1095 spring is what I run in all of them. I've personally never had a need to run the Tubbs flatwire spring, because the EA1095 just plain works. Just received some more parts today - DSG Arms was out of Armalite AR-10 Carbine Receiver Extensions, so I just grabbed a VLTOR A5 receiver extension, H3 buffer, and another EA1095 spring. Works like a champ on these .308s... That spring will be fine with Slash's XH buffer, too...