Hey,
thought this may be of interest:  Uppers made by Alcoa, north of Spokane WA that are DOD production over-runs
being offered through Snake River Armory, of Star Idaho here:
http://www.snakeriverarmory.net/FN-M4A3-Mil-contract-Stripped-Upper-Receiver-p/fn-m4a3-up.htm
for $75.  They are anodized black, and feel "silky smooth"!  They'll make you want to sneak it into bed and caress  it against your cheek while making love!!!!!!!!!!!!!  No shit!!!   (sorry).  OH man, they are hot!
I purchased one and it is marked" F A" for FN Alcoa foundry. The texture is incredible, edges are unreal.
I have an Aero Precision, Olympic Arms, Anderson, and Cerro forge (anodized and in the white) upper.  NONE are in the same class.
I'm not getting anything for this plug, just want to pass on this offer.
I don't think you can obtain a better upper, unless you want some custom brand of the day's etching or groovy lines cut, or has the endorsement of Johnny Whiz Bang! (<not me . . . honest!)
Plus, $75!
Also, they have a billet upper that looks surprising similar to the Spartan upper I posted about last week.  It looks nearly exactly the same, less the Spartan logo and the MOAON AABE  or Molon Labe, (sorry I can't make the Greek symbols!) But, both are 7075 T6, and have the detachable forward assist/shell deflector module. A couple lines look a little different, but this, probably from the same prints with minor differences to avoid copyright infringement.  Otherwise, the same, and for the same price: $110.
Anyway, just wanted to pass this on.
$75 for a DOD FN !  FN Arms America (I think), who landed the contract following the collapse of Colt, what 4 years ago now?
Anyway,
Rob