I've decided to begin on my AR endeavor, I'm buying a stripped lower from Spike's Tactical and a parts kit, along with a telescoping stock and I'll be putting those together in the coming months (haven't bought it all yet, piece by piece). That's the easy part, very straightforward.
Now my question is this: on the ST website it wasn't as obvious to me on which parts to buy for the upper, what all do I need and what barrel styles, lengths, thicknesses would you folks recommend and what exactly do I need to purchase to have a complete upper for me to assemble? Really I guess I need a parts list for that upper. For the lower it all comes in a baggie

Oh yea, I know what the barrel twist physically is, but how does that translate to accuracy, power, etc?
Thanks a bunch, going this alone is a little daunting at first, earlier today I had no idea this was mainly an online affair
