A USGI web sling works fine.  Since you won't likely be using a tight shooting sling on this type of rifle, remove the noisy spring clip that hooks onto the butt sling swivel, and simply loop the sling through.
The OEM rear sight is a flat affair with a peep aperture.  Problem with this set-up is that sunlight has an annoying way of glaring off the flat metal surrounding the aperture.  Better by far is the Belgian-style hooded rear aperture, which eliminated this problem.  Available at time of purchase (save $), or separately.  If you have a very wide face, get the High version, along with a correspondingly high front sight post.  For most people, the standard height seems to work fine.
The original Safety/Selector lever is small, short, and difficult to manipulate, especially for people with short thumbs, or while wearing gloves or mittens.  The solution to this problem is to modify and install an L1A1 selector lever.  While this takes some minor fitting (hacksaw, bench grinder, dremel tool, cold blue solution), the result is much easier and quicker to manipulate.  You have to try this to feel the difference.
The little cleaning kit which fits in the pistol grip is kind of neat.  The kit is a long and short tube, joined together, with a baseplate and attached spring clip lock.  The US-made pistol grips lack the small cut-out needed to secure the unit, but a few moments of careful use of the dremel tool and you're in business.  The kit contains a brass pull-through, with fittings for a patch tip and brush, both included, as well as a small amount of lube oil.
Get the plastic handguards at time of purchase, and save a bit.  They run a bit cooler than OEM steel, bipod still fits, and match the rest of the furniture.
The standard Hogue hand-all grip cover fits with minor trimming at the top rear, and feels great.
For carrying mags, use USGI AR 3x30 rd mag pouches.  After you cut out the dividers, two FAL mags fit perfectly.  A mag loader can be securely carried in one of the grenade pockets, the securing strap going through the loader.  Hope this helps.

Quoted: Raf, I priced one of these for my cousin Saturday. The dealer quoted a price of, I believe, $837+tax for the full-length model and $887+tax for the carbine. How do these prices compare to other dealers? Thanks!

Dealer cost from DSA (as of a few months ago, maybe still applies) was $795+ Shipping.  So your price sounds like your dealer is just getting a modest transfer fee.  I'd go for it, as long as it is from DSA.  Can't speak as to the others.

Quoted: raf, I would like to make some alternate suggestions to your Random Thoughts: 1.) Dont just 'get by' with a USGI sling. Get a good Tactical Sling. They keep your weapon at ready, and take the weight out of your hands. You can even use them like a conventional sling.

Sorta agree.  Some tac slings can be a hindrance because of their complexity, and can prevent easy weak-side transition.  Jury's still out on this one, but I'm open to suggestion.

2.) The AR 3-mag pouches are just a little too tall. M-14 mag pouches are truely perfect, and common, work with ALICE clips, and are cheap. They also have the grenade side pouches. The Canadians also make an outstanding pouch.

Glue 1 or 2 closed cell foam spacers in the top and bottom of the pouch.  GI sleeping pad is ideal.  Don't forget drain hole in bottom.  This solves size issue, and protects the mags as well.

Thanks all for your comments!