What length - 14.5, 16, 20?

Braked or not? If so, which model?

M4, H-Bar, fluted, free-floating w/ aluminum handguard?

What sights, A1, A2, A3?

Scope, Reddot, Reflex II, or what?

Good question.  But I think any post-ban rifle is a poor CQB weapon due to lack of flash suppressor.  However, I decided to start a M4gery project based on "poser-CQB".

Bushy flattop upper (v-match)
14.5" M4 barrel
AK brake (pinned and welded for legality)
KAC RAS handguards with vertical grip
Reflex II (RX06-14) 12.5moa triangle
KAC 300m rear iron sight

Once again, the use of a loud as hell muzzle brake on a post-ban weapons ruins its tactical utility.  But, I think naked barrels are ugly. So, I will use a muzzle brake since I don't really plan on using my rifle for "CQB".

Clearly you want the 20" barrel, put a large brake like the JP brake on it.  Make sure it's an HBAR, and use a non-vented aluminum free-float tube.  A flat-top upper with a real scope with atleast 16x magnification and a bullet drop compensator.  Don't waste your time with any of those over-priced zero magnification dot-sights.  [:P]

CQB?  Would'nt you want a fairly short barrel on a CQB weapon?  I mean engagement distances are going to be fairly short right?  How far would be the longest engagement distance, would 100 yards be far enough?
Since this had to be a post ban weapon I would go with 16" barrel, KKF A2 brake, B.M.A.S. 3 rail gas block with sight, flat-top upper with M.A.D. rear back up sight, and a Aimpoint Comp ML. Oh, yeah I would be firing handloads loaded with a 52gr. bullet. And I agree 100% with 8200's last sentence.

He's not going to be using it for CQB...except maybe at the range against a hoard of charging silhouette targets.  

Get something that looks "cool".  It's a poser gun anyway.  Don't get me wrong.  There is absolutely nothing wrong with wanting to look "cool" at the range.  Just keep both feet firmly rooted in reality.  You ain't doin any CQB.

I happen to like ARs that some people think are set up for CQB.  They're not.  They are set up to make certain anti-gun idiots nervous.  i like evil, ugly guns. [}:D]

If you look at the units that are the "experts" in CQB (eg. SEALs, British SAS, LAPD Swat, etc.) you will notice that NONE of them use electronic optics, fancy grips or forearms, or specialized triggers, or whatever.  Usually a "plain-jane" 16" carbine with a mounted flashlight is the perfect tool.
Spend the extra money in practice ammo.  All of the expert instructors from reputable schools (eg. Gunsite, ThunderRanch, Front-Site, etc.) agree.  And being a veteran tactical officer and firearms instructor, I must agree.
Hope this helps,
***ptp

I've shot my AR at night with it's 14.5inch AK74 muzzle brake, it's muzzle flash is impressive that is for sure.

You're going to be blinking like a freaking idiot after you fire your first shot and you are trying to regain whatever night vision aquity your eyes previously had.

Some people aren't much of a believer in tactical lights and they believe it's just a giant beacon that gives away the shooter's position.  Knowing when to use and when not to use a tactical light is a strong concern and a proper concept of how to use one is recommended.  Personally I see a use for them when you understand how to use it and not use it so as you don't give away your position too soon.

As for low light situations a reflex type sight is a welcome addition, I chose a Trijicon Reflex because of the fact that it doesn't require batteries and it is always on.

Will my rifle ever be used in a defensive situation, probably not.  I'm very affraid of ever having to fire any of the AR types indoors without hearing protection, yes I value my hearing that much.  Maybe if I get a set of electronic ear muffs I'll change my opinion.

As for now, I saw a need for a quick swinging AR for occasional use in a action rifle match or 3 gun competition.  It will also see double duty as a "coyote gun" for using occasionally on private property to dispatch the random yote that should happen by during the hours of the night.  With the Surefire 500A on the front of the gun spotting out to 100 yards becomes no problem, the Reflex sight in conjunction with the lighting effects of the Surefire make for one hell of an easy aiming package.

my Bushmaster Shorty AK
[url]http://home.bak.rr.com/varmintcong/bushmastershorty.html[/url]

You never know, maybe the man needs to flame some rats in his basement.

Speaking of CQB, which if you ask me for us civies is probably more like the "home invasion" scenario, what if you had a Sure Fire on your rifle? Would the extreme brightness of the light not obviate the need for a flash suppressor?

You might go deaf, but hopefully not blind.