What should I look at for parts?  Right now I have a stripped Aero lower and a Larue MBT from their $99 sale.  I'm firm on the SB Tactical PDW brace.  I was thinking maybe an 8" barrel, but then researching I see that the actual Honey Badger used a 6".  What twist rate did it use?  Can 6" .300BO barrels be easily had? If so, do they use pistol length gas systems or something even shorter? Any good deals I should check out right now?

I would model after the newer 2.0 from the Q

I will likely be doing a PDW brace also .  

In to see some of the suggestions.

Iirc it's a suppressed barrel. My faux hb is 8"

Well, I purchased a Maxim Pdw brace while they were on sale for the NRA show.

Now to decide on an upper: build around a 6" barrel like the original or go with a 8"-9" factory upper (BCM, PSA, etc).

Any opinions one way or the other?

Cut the difference. I have the maxim on a aero lower and a aero COP carbine upper with a 7.5 from BA and it's been good.

Might want to wait for the Tailhook mod 3:

One that I recently completed.

I chose a Noveske 8.5 inch barrel and it will be wearing a Griffin Recce 7 if the stamp ever clears. (Has a Pig right now)These two choices insured that it was 3-4 inches longer than the real Honey Badger. I would have gone with a KAK Baby Blonde 6 inch barrel. But the Suppressor paperwork was already in before I decided to go down this path, and it's rated for a minimum barrel length of 8 inches. All that said, I'm pretty pleased with the Maxim brace. Really shortens the whole pistol compared to the Shockwave. I tightened up the Velcro strap, and it helped make the rubber part feel more solid.

That brace works very well