www.falfiles.com
Let me toss some gas on this fire. The FN FAL will vary wildly in quality, depending on country of origin and rifle builder. As another poster said, DSA is probably your best route. Work with them directly to save money. You can probably expect 2-3 MOA performance out of the box with a DSA rifle.
If you want better accuracy than that, go with a Springfield M1A1 (M14). It will cost you 2-3 times as much, and mags are around $50, as opposed to $5 for a FAL. Have fun shopping!
The AR-10 clones in .308 (7.62x51) can be extremely accurate. Example: The Knight SR-25 1/4 inch groups at 100 yards are claimed.
The same applies to the AR-15 clones in 5.56x45 (.223 Rem).
The biggest problem with the AR-10 and AR-15 is fouling of the gas tube. This was due to ammunition containing powder with a high calcium carbonate content. The calcium carbonate would build up in the gas tube, blocking it. It is not as much problem at present, because of improvements in powder technology. Use ammunition with ball powder.
Any firearm must be kept clean, for maximum reliability. I believe the Ar-10 and AR-15 clones are very easy to clean, since they break open at the breach, so the bolt carrier can be removed and a cleaning rod inserted from the chamber end of the barrel.