I will be using a 24" HBAR and I'm not sure what upper to get.

My first choice is the A2, but I would like to use optics as well. Will a scope sit way too high on the handle?

Of course the A3/A4 flat top suits the scope much better... but if I keep the front iron sight, will it interfere with any of the topics?

If I went with the A3/A4 route, what should I get to use iron sights? A flip-up rear sight, removable handle, or ?

I plan to shoot mainly for accuracy on a bench or in competition shooting up to 500 or 600yd, so the rifle won't see any tactical carbine matches.

What buttstock should I get? I hear the M4/CAR stocks are real wobbly and that the A2 fixed stocks are the best for accuracy and durability?

Thanks in advance

Definately the flattop.

Stock?  A1 if you're under 6'4" and A2 if you're 6'4" or taller.  Cav-Arms makes new production A1 stocks if you don't want to use a surplus stock.

If I'm really close to 6'4" (I'm 6'3") ... what should I do?

I did have trouble with the M16A2 because it felt weird trying to get the right sight picture without leaning my head.

If your shooting 'square to the target' the toe of the buttstock should be in your shoulder - this raises the irons high enough so you don't have to drop your head.  Buttplate height is the same for A1, A2, and M4 stocks (the older CAR stocks had a smaller buttplate).

If you're looking for a nose-to-the-charging-handle type of sight picture then you will need to bend your head down to use the irons.  If you can live with the A2 I'd say go with that as they often come with the gun and it won't cost you extra.  If you find it difficult/uncomfortable to get your nose near the charging handle (it should be 'just' off of it) then go for the A1 stock.

I did find the Cav-Arm A1/C1 stock... it's advertised to be 5/8" shorter than the A2 stock (10.5" - 5/8" = 0.9875")

I found a "LE Tactical" stock that looks like Bushmaster's Stubby Stock. Would this work? It won't cost me extra to add onto the rifle kit.

Quoted: I did find the Cav-Arm A1/C1 stock... it's advertised to be 5/8" shorter than the A2 stock (10.5" - 5/8" = 0.9875") I found a "LE Tactical" stock that looks like Bushmaster's Stubby Stock. Would this work? It won't cost me extra to add onto the rifle kit. www.model1sales.com/images/letactb.gif

The LE Tactical is WAY to short.  It's designed for 'tactical shooting' (square to the target) for LEOs with body armor.  If you're not wearing body armor you will need to get a 1" spacer to use it comfortably.  

If you're looking for more of a 'Tactical' stock then I'd advise to get the Sully stock - its a bit more than an inch longer than the LE Entry, plus it comes with a 1" spacer for the bigger guys (even with the spacer its a little bit shorter than the A1 stock).

I've tried all of them.  For me (5'8") the plain Sully is the best when I square off to the target, while the A1 is the best when I 'blade' to the target or shoot prone.

Since you're getting a 24" HBAR I'm betting you're going to spend your time prone or on a bench.   Which means the A1/A2 type stocks are what you should be looking at.

Yep, you're right - I was planning to do prone/bench shooting only.

I was actually going to use a 1" PAST Super Mag Plus recoil pad. Would that even things out? I'm recoil sensitive because I'm not a big guy... 6'3" but only 170 lb. Even with something like 3 ft-lbs of recoil energy, if it hits me in the shoulder in the right spot, it gets sore.

With just a T-shirt, I felt the M16A2 stock was too long. But now that you have me thinking about this.... the Sully stock sounds like the best way to go.

Quoted: I was actually going to use a 1" PAST Super Mag Plus recoil pad.

Recoil Pad on a .223 - especially one as heavy as a 24" HBAR? (we're talking almost 9lbs of weapon w/o optics or loaded magazine).?  If you wanted to dampen what little recoil that is left you can put one of those 3lb lead stock weights in the stock...

Recoil is not an issue.  

Adding 1" to an A1 stock would make it longer than the A2.

if it hits me in the shoulder in the right spot, it gets sore.

Pull the stock into your shoulder.  If you hold the stock just off the shoulder (or on it lightly) then the rifle can bang it.  With the rifle in your shoulder you won't have a problem with the soft recoiling .223.

With just a T-shirt, I felt the M16A2 stock was too long.

Then it sounds like you need an A1.

the Sully stock sounds like the best way to go.

I love the Sully for what it is - a great TACTICAL stock meant to be used on a square range.  When used in most prone positions - or from a bench it puts my face way too close (I can eat the charging handle if I wanted to), and I'm a good 7" shorter and a lot beefier than you are...

Which is why my 'precision' rifle wears an C1 from Cav Arms (their version of the A1).

A3 upper

trapdoor stock

Forest:

I actually started shooting with a VEPR K (RPK) with a 16.5" heavy-barrel hammer forged and chrome lined (0.610" OD), weighing about 9 lb w/o mag in 7.62x39 (shoots 1.5 to 2 MOA with good ammo)

I would tighten up my hold of the rifle with the buttstock into my shoulder. This would cause the most pain for some reason as it would somehow send the vibration/shock through my neck? and I'd just have a nasty headache the rest of the day. Of course this was still only 7.62x39, about twice the recoil of .223 (which isn't a whole lot to begin with) but I'm just recoil sensitive.

Just out of curiosity, how long is the LE Tactical stock? The VEPR K's stock is 10.5" from the receiver and experimenting with different lengths, a buttstock that was about 2-3" shorter would give me that "nose to the charging handle" cheek weld.

Quoted: Just out of curiosity, how long is the LE Tactical stock?

7.5" - the same as a Telestock fully closed.  The Sully is like a Telestock opened to the 1st or 2nd position.

BTW if you really are recoil shy you'll want to stay away from the short stocks (Stubby & Sully) as they use the shorter/lighter CAR buffer system.  The shorter buffer system give the recoil a 'sharper' feeling compared to the softer feeling Rifle buffer/spring combo.

Recoil of AR and AK can't really be compared as the AR is so much softer.