Welcome aboard, Marco!
Since I'm
not a team member [yet] I don't have to respond with "get both", and I won't (for the time being).
I'm also (fairly) new here, but lurked for ages (several years) soaking up info.
I finally decided that if I was going to spend money, I'd build
eactly what I wanted. Because of the modular design, if you can change the plugs on your car, you prolly have the mechanical aptitude to assemble an AR.
Some suggestions:
Take your time, reasearch here, take your time, and do more research here. Then build yourself an AR. If you're really hot to buy a "complete" AR, both RRA and Bushy are excellent companies to buy from. Realize that you'll end up spending half-again as much as the rifle in add-ons sooner or later.
Buy what you want, but
ask questions here to determine what you want first. I thought I knew, and then was sent in other directions by the good folks here (based on my criteria, they steered me in the right directions).
Now to your specifics questions:
There is no "collector value" in a pre-ban rifle outside of the few states that still have a AW ban. You're in Kansas (ie no state AWB), so the "pre-ban" status now just means "used" since the Federal law sunset last week. Buy new.
If you want a colapsible stock, look for a 6 position M4 stock, or a Magpul 93A. With either, the multiple adjustments will come in super-handy. The Magpul stock is expensive, but worth every penny IMO. Once set up, it can also be utilized as a "2 position" stock (it can be set with a preset so that you have two, almost instant positions; full collapsed, and open to your LOP preference).
Opinions are split on the permanent flash hider. In true Arfcom tratition, I ended up buying both (two different uppers)
. It
is the way to go if you can't or don't want to SBR your rifle. You won't notice a weight difference between them, if the barrel profiles are the same.
Two stage triggers are very nice for National Match and varminter guns. At the same time, a little work (search for "The 15 minute trigger job" here at Arfcom) and you will have a single-stage that is very precise. More of my opinion; don't bother with the springs, just use the mild abrasive to smooth the bearing surfaces.
If you want to mount an optic, go for a flat top upper.
I hope that helps!
-FMD