I'd buy a basic no frills machine from a reputable company that's been around awhile. Concentrate on barrel & bolt carrier quality. A good trigger if money is left over. Windham, Rock River come to mind unless news is they have really started screwing up. Companies like these built 10's of thousands of AR's before 90% of most all the other companies were ever started..

Ruger? Really? hope they're getting better, but still just a small sideline for them, not the main course like with some companies. Lots of startup probs. with their gas gun in the beginning, like, how do screw up an AR. Ruger did.

All the forearms, grips, whizbang stocks, etc. might be helpful, but when you get right down to it, that stuff in just streamers, reflectors & baseball cards in the spokes.