Have you seen the Nemo Arms barrel? I was/am looking at the Fulton ultralight barrel and saw Brownells has the Nemo barrel. It's .750 vs .625 so it's a bit heavier. I thought the extra size would be good for a suppressor.
http://www.brownells.com/rifle-parts/barrel-parts/rifle-barrels/ar-15-m16-308ar-nitride-barrels-prod54801.aspx?avs|Make_3=AR%20xzzx308