The owner of one of the local gun shops I frequent has two SR25 rifles. A sniper 20 or 22" setup and a tactical 18" setup. He took the tactical 18" to a shoot last year and he was consistently nailing a 6x8" steel plate at 600yards using M118 ammo. It's a sweet rifle but the price of over $4.5K without optics (He's was using a Nightforce scope (I think 3.5-15x) with it, which costs over $1.5K by itself).
If money is NO object, that's the setup to go with. Everyone I know that has one, rants how sickly accurate they are.
If it is an issue (as it is with most of us), You could get a built-up DSA FAL with an RIS that will shoot 1-2 MOA, 10 adjustable gas settings, can use 20 or 30rnd mags, and is a short stroke piston setup for around $16-1700 brand new.
The Socom M14's are great rifles, but a bit on the heavy side and are not the best platform for optics. They are very accurate, reliable out of the box though. Pricey also.