I'm in the process of building my 2nd AR and this is what I am planning on using:

Lower:
Rock River Arms Lower (have)
Unknown manufacture parts kit (have)
Rock River Arms 2 stage trigger
Magpul M93B Carbine Stock
MIAD Modular Grip Kit/MIAD Grip Core (ordered)

Upper:
M&A A3 Flat top upper (ordered)
Unknown manufacture parts kit (have)
Badger Ordinance Tactical Latch
Bushmaster A3 type removable carry handle with 1/2 MoA rear sight
Unknown Manufacture 16" bbl (have) w/Medievil Muzzle Break( http://www.troyind.com/Finished/Med.%20Muz.jpg )
ARMS S.I.R. #45C (have)
ARMS #40 Low profile stand alone flip up rear sight (have)
EOTECH 512.A65, Rev.
Redi Mag
Surefire flashlight with pig tail (have)
Not sure of the sling yet.
Trijicon Front Sight

Is there anything I am missing or change recomendations?  My 1st AR was just a basic A3.

Thanks for the advice/responses

Why are you buying a removable carry handle, when you already have a BUIS?  

Save the money.  

I also wouldn't spend money on that FS...... I would buy 2 Phantoms for the price instead.



Lastly, make sure your barrel extension and upper receiver are going to mate up correctly.