Alright, here is why I would rock an M1A Loaded with Leupold scope over an AR in .308 configuration. The action is drop dead reliable. Unless you get gobs and gobs of mud or sand in the action it will always go boom. It also has one of the best triggers of any semi auto. It is accurate (the loaded's match barrel is a nice addition
) at range. Roughly 1.5 MOA with factory ammo, sub MOA with hand loads. Magazine size is 20, which is about all you will find in a .308 semi auto. I'm sure there are some 30 round magazines out for all of the .308 rifles, but 20 seems to be a great even number.
Of course it's not a carbine (and please don't buy the SOCOMII, it's not very accurate (3MOA with factory, 1.5MOA with handloads), and it's not even short at 44.5" but it's worth every last inch of that. I guess the M1A Scout's are accurate, but it's not "carbine" length by any stretch at 36" long it's the same size as a full M16 :O
.308 isn't a good self defense round, unless your area of defense includes perpetrators at 50+ yards, good luck defending yourself in court with that large of an area
In the house, one of his shotguns will suffice better than his handguns or a rifle of any type, but for hunting it's a great round with plenty of accurate and efficient rounds for all sorts of game.
The handgun is pretty obvious, any of the modern polymer handguns are going to be lighter than a 1911, accurate and reliable to boot. You can't go wrong. I LOVE my XD45 Tactical, it's stupid accurate (even for a standard XD) but you can't go wrong with the M&P45 or the Glock 21. If he's a big 1911 fan, the M&P and the XD will be better fit for him as it is more like a 1911 than the Glock is in shape and function (grip angle and all that).
As for the FN, well, I'm not a huge fan of the SCARs (either caliber), neither in the looks or the functionality department. It's just too expensive for what it offers and not really offering much over other options. A .308 AR is going to a better investment than the SCAR will be and just as accurate if not more accurate. Cheaper too, more abundant help and support should something break. I dunno, it's just not my cup of tea.