If you can get the M1A with all USGI parts (or at least as many as possible as I know some would need to be modified)..then they'd be on equal footing. A lot of the newer M1A parts are made by Springfield now, and aren't quite up to the original USGI quality...
FAL magazines are cheaper, hands down, at least right now. For the price of 10 M14 mags, you can pick up easily 2x the number of metric FAL mags.
It's easier to mount a scope onto a FAL (new topcover).
Reliability is a wash; if maintained, both will continue running long after you die.
Accuracy...the M1A is better with irons; the FAL's rear sight is not attached to the upper receiver, and depending on how tight the upper to lower receiver fit is, it's POI could shift. However, the M1A is not really a scope-friendly platform. It's mounts aren't as sturdy as a FAL topcover with a rail would be, nor can it be readily removed and reattached with a guaranteed zero hold. Most M1A mounts are basically "Stick it on and don't take it off" types, though if you get scoperings with quick-detach functionality, it's not a big deal. It just hinders cleaning everything (removing the bolt necessitates removing the scope mount).
Toughness of design...well the FAL is still an active use/issued arm. The M14 is only available in surplus form from the US Gov't, and only given as aid...they're not really an issue arm anymore to anyone.
Field survivability, see above. The FAL is still in use in armies all over the world. It must work pretty damn well.
Resale value on them will probably be about the same (I wouldn't know; I haven't sold either of mine
)..