Fulton Armory is a Great Choice - you buy them direct from Fulton and have it transferred to you FFL - Clint McKee makes one hell of a rifle.
http://www.fulton-armory.com
Also check out LRB Arms they make the only USA Made hammer Forged receiver plus the wait time one getting a complete rifle is less talk to Lou, he's a great guy.
http://www.lrbarms.com
You could also have Ted Brown or Tim Strait (War Bird) build up your bare receiver from the ground up, they are two of the best gas-gunsmiths in the country.
Either way you can't go wrong and you will be getting a far superior product to a Springfield Inc. M1A
-toolman9000