It would work for pretty much any CQBR gun - ideally with a blank receiver so you could get the Diemaco engravings on it. Anyway, here's the list for anyone that needs it.
FLASH HIDER: standard A2 or 4-prong Surefire FH556-216A
SUPPRESSOR: Surefire SF556
BARREL: 10" or 16"
FRONT SIGHT: standard A2 or reinforced A2 w/ filled gap, neither have a bayonet lug
HANDGUARD: KAC 7" drop-in RAS
FOREGRIP: KAC screw-on foregrip
RECEIVER: standard Colt w/ Diemaco engravings
PISTOL GRIP: 'Stowaway Storm' or standard A2
OPTICS: EOTech 552, Trijicon ACOG w/ mini Docter sight or Diemaco carry handle
STOCK: CAR-15 style with recoil pad or Magpul CTR
Hope this helps anyone.