I would go for an Armalite. They've been around for a long time, and the bugs have been ironed-out. Plus, you cannot go wrong buying from Wolverine Supplies, the Armalite importer.
In terms of ammo, just remember that soft-point is a no-no in the Armalite, and probably in all of the AR variants in 7.62. Soft-point rounds will jam during feed.
My own observation with the AR10 is that it's a very tight gun when new, and can take a bit of shooting (a few hundred rounds) before it is properly broken-in. Until that point, I experienced the odd problem, mostly ejection issues. Your mileage may vary.
All AR10 models are restricted.