HAN....learn me on the AR. I'm looking to build one that's a decent gun, but not super expensive. Should I buy a completed lower, or buy a stripped one and build it myself? Is necessary to have mil-spec parts in the lower? Is having a free float guard preferable? I do kinda like the look of the free floats with a stainless barrel. Probably going with an optic of some sort....which upper style is most conducive to that? Iron sights + optic or choose one?

Companies to stay away from? I'm assuming it's better to get an aluminum lower rather than polymer.

Thanks for helping a noob.