Alright, pretty new to this game.  But, I have decided I want my 3rd build to be a 6.8.  That being said, here is what I would like and please lead me in the direction I need to go...

RRA Lower (already have this)

??? BCG
16-20" barrel (could use some help on this)  looking for a fluted, straight barrel with MB or FH milled into barrel (similar to a mag-na-port type)
Not sure on gas system style/length
some sort of ARMS SIR
some sort of collapsable stock (not standard M4 style, maybe Vltor etc)
All done in desert camo

I guess the biggest question is the barrel.  Where or can I get what I am looking for?  Who will assemble it?  

Thanks in advance fellas.  Geel free to insult me or ask questions.  As previously stated, I'm pretty new

You can try to look in the FAQ to start with in the AR15 general discussions tacked at the top.

Most of the big dealers on AR15.com are offering their own 6.8 parts and assemblies. I think the Mid length will be the most reliable for the 6.8.

Thanks for pointing him to the FAQ thread, Tim.  WR, that's the best resource.  For vendors, check the Equipment Exchange.   I recommend MSTN without qualification, but there are more "budget" options.

WR-

Your best bet for the barrel is to use a 16"-18" with a midlength gas system and a muzzle threaded for 5/8"-24.  Then you can use whatever muzzle attachment you want: brake, comp, flash hider, or a real suppressor.

There are lighter and more stable/rigid options instead of the ARMS SIR. For a railed tube, the Larue is probably the best.  If you don't need 100% rail coverage, the PRI tube is very nice.

You can use any decent bolt carrier - it's the bolt itself that is 6.8 specific.

The lower is not 6.8 specific at all, so you can do whatever you want.

-z

Sorry fellas.  I meant to add in the post that I have indeed reviewed the FAQ.  I was looking for VERY specific things and was not sure if anybody could point me in the right direction.  I guess I will just contact the suppliers from the EE on the 6.8 barrel.  Thanks guys

Barrel Suppliers?
For low end there is Model 1

For high End you've got Wes at MSTN.Biz (heck he can do the whole upper or rifle).

For custom you've got Randall at AR15barrels.com.

WR-

Good luck finding what you want.  Keep us updated!

I'm just finishing up my 6.8 build.  Here is the parts list:

T marked flat top courtesy of ADCO
White Oaks 20" barrel. Stainless heavy barrel, unfluted. Came with a 6.8 bolt.
YHM Rifle float tube kit, FS mounts on top rail
Arms 40L
RRA bolt carrier and charge handle
MSTN QC comp


This is going on one of my Ameetec lowers with a AFRX stock on it. I'm going to put a target scope on
either a Larue or ARMS mount.

Just as a side note. It seems the panic to acquire 6.8 parts has already started.  Midway is out of
brass, they just got dies for 6.8 back in stock and I can't find anyone who has .277 110 gr. V-Max
in stock. Barrels seem to have vanished. PRI his some, $$$. I expect the parts situation to get worse rather than better (look at RRA and Bushy and that's standard stuff!)
Good news is factory ammo would seem to be starting to appear.

I contacted Bushmaster regarding their plans to offer parts/complete uppers. Got a quick response-

" Bushmaster is looking into building some proto types at this time. They may be available in the spring but no firm decision has been made.
             Thank you,
             Jim Eden, Tech Support "

FWIW

Thanks again guys.  
I guess maybe I should start doing some further investigating.