I would just do a kit. You will end up spending a shit load on shipping for small parts and the individual parts are most likely more expensive that a complete assembly. You might have good luch picking up used parts in the EE, though. Otherwise, I would get a kit.
I just ordered a J&T kit and it seems to be pretty good. I would recomend their kits and I think the A2 and CAR-15 kits are $469. Add a Superior Arms lower from the EE at $75 and you have a $544 AR-15 A2.
Here are the details from my
last most recent build:
Sabre Lower (shipped and transfered)......$160
J&T M4 kit.............................................$569
Magpul CTR milspec assembly.................$150
Magpul Miad Grip.....................................$34
Troy BUIS.............................................$140
Troy MRF-DI Handguards........................$160
Verticle Front Grip....................................$30
Surefire G2 Light and mount.....................$90
Magpul Ladder Rail Covers........................$40
Larue LT105 Mount.................................$110
Trijicon ACOG TA50-4..............................$475
Sabre extended A2 FH and per install.........$70
18 magazines from 44mag.com...............$190
_____________________________________________
Total Cost (not counting shipping) $2,218
bad part is that that total does not even include ammo or a sling.