Try 68forums.com. You'll find more there than you imagine, suppliers, industry professionals, and a helpful atmosphere. They shoot other calibers, too, it's an even handed appreciation for what the 6.8 offers.
Having another upper isn't exactly the cheapest way to build. For two calibers, it offers a quick change, a familiar and universal platform to shoot from, and two different directions in use. The 5.56 can be a tactical quad rail, the 6.8 a long handguard with low powered optic good out to 450m.
Check your states hunting regulations, they are interesting. MO allows any centerfire cartridge for hunting - any - but no lights or lasers. So even 5.56 is now ok, but 6.8 does offer more. I'm building one with rifle length handguards in Foliage Green. There's enough rail space on an A3 upper for hunting use, and the polymer handguards don't suck heat out of cold hands like a quad rail or tube. Consideration for the hunter is more important than impressing a occasional squirrel, even the ones not in the parking area.
Go 6.8, it will become the first choice of a lifetime of hunting.