You shouldn't have any problems. But as far as I know the 7.62 NATO round is a mil-spec round and it's illegal in the USA (some states anyways). I would recommend some Hornady .308 Win SST ammo, that will do the trick.
For me - looks more like Para version of SA-58 (ya know, American variation of FN FAL). And I don't agree, that it is too "tactiC00L" - FAL, L1A1 SLR, or any other version of FAL are normally chambered to 7.62 caliber - it's big, powerful, BUT makes gun kick pretty bad… especially shortened and Para ones, so grip is pretty useful. And holographic sight - can make difference, especially in CQB.
I'm sorry you feel that way, but nowadays the picatinny system is the easiest and most reliable way to easily mount optics and other attachments to a gun. It gives the weapon the versatility that modern warfare requires. If this is "tacticOOl" for you then okay!, just don't go around criticizing things when you have 5 year-old drawings in your gallery. Just saying
Still, the pressure each shot produces and the huge amount of shrapnel you get if you hit a wall for example is extreme.. no matter what ammo you choose. But I love the FAL no matter where I'm using it, I just wouldn't like to be standing on the other side of it
Just remove the dust cover (slide it out) and slide the DSA scope mount in (you will have to do some screwing after that, and not in the kinky way) pretty simple. Just make sure you order the right mount. They have different mounts for fixed stock and para FAL's
You can see the right side on my other fal pic --> [link] not the greatest quality but it's what I got :S Though the scope mount on my long range fal is a weaver, and the cqb is picatinny. I'll take more pics when I have the time.