I currently have a fully assembled Bushmaster lower receiver with an ACE ARFX stock.  On Friday, I'll have the cash in hand to order an upper.  This will be my first AR.  What upper would be my best choice as I learn proper marksmanship, care, and handling?

I'm torn between a standard 20" post-ban with muzzle crown (so I can have it threaded later) or a pre-ban M-4-style upper.  Both would have chrome-lined chambers and bores.  A-3 uppers with detachable carry handle, and a standard fixed front sight.  If I order the pre-ban, it has to sit sealed in the box at someone else's house until Sept. 14th rolls around.  If I order a post-ban, I can start shooting right away, but then I'll need to either thread the barrel or order a second upper in three weeks.

What about free float rails, for when I want to put on a forward grip or attach lights?

My choices are down to upper assemblies from Adco, J&T, and Model 1 Sales.

Thanks for your advice!

Go with ADCO and preban.  You won't regret either decision.  And with shipping, your wait will be minimal.

ADCO has a couple choices for freefloat tubes:

Knight's Free Float RAS (+$330)
Daniel Defense 7.0 (+$320)
PRI Free Float Tube (carbon fiber? +$360)

Anyone have links to reviews on these options?  Which would you recommend?  Could I buy them cheaper and install them myself, or does it require removing the barrel from the upper receiver?

Oh, and now I need to add this to my consideration list:

http://www.bushmaster.com/shopping/uppers/pre-ban/bura3b16sir.asp

"Pre-Ban 16" A3 S.I.R. Upper Receiver / Barrel Assembly (shown above) is complete, test fired at the factory, and ready to snap on to your Pre-Ban lower receiver. It includes the ARMS S.I.R. System Military Version which does away with the Delta Ring Assembly on the Barrel Nut."

$935, plus I'd need to order a charging handle and bolt assembly.  From what I've read, Bushmaster uses 4150 steel for their barrels, all chrome lined.

Hmm.  I've also found that LMT barreled uppers are available from:

http://www.bravocompanyusa.com/M4Uppers.html

LMT M4 16" Upper Receiver is Price at:  $485 (no b/c/ch, no grips)

By the time I add a b/c/ch and a rail system (DD 7.0, $265 new?), I'm close to the Bushmaster.

Anyone care to comment on LMT v. Bushmaster?