Quoted:
Thanks for the quick reply guys. The pics on your site really do a good job of supplementing the info I've found here on AR15.com, Knife_Sniper, thanks.
Sounds like billet is out, no real gain for the money, that jibes with my experience (I'm a bike mechanic by trade and generally billet in that industry is weaker and more expensive, albeit a little lighter).
I'm still debating how I want to go with the gas system, seems like the Del-ton might be a bit finicky, since it uses a rifle length system. Perhaps building a mid-length dissipator would be a better idea? I think that might open me up to complications with barrel mounting a front sight, due to differences in the ID of the FSB and the OD of the barrel?
Any opinions on rear iron sights? are the fixed mounts from Daniel Defense and Troy Industries better than flip ups?
As someone above pointed out, there is no wrong answer, and that is the great thing about ARs, they are all great, and they are personal. Outside of recommendations to get parts from good manufactures that use Mil-Spec or better processes you are GTG. I would highly recommend getting a 5.56 chamber and chrome on the chamber and bore. Walk away from anything that is not. That will meet your SHTF requirements, and it will make the gun last longer. While someone will chime in on the downside to chrome lining (accuracy) you arent going to see that unless you are a SUPER shooter and if you are shooting long distances all day.
Now for pure opinions... which is the heard of AR15s.
Got with a midlength gas system, and a fixed A2 FS. Go with the Magpul MBUS, save the 50 to 75 $ and buy a good mount for a good optic. Again personal opinion is that if my optic fails, I am likely dead, or about to die, or $hit is really really bad, and I will be running and shooting from the hip, so I place little importance on BUIS... But this assumes you buy a decent optic, like an entry level Aimpoint or better. I like adjustable stocks too, but that is because I like a short length of pull, but keep in mind for someone that is much taller than I am, some adjustable stocks provide longer length of pulls than A2s, but A2s provide a nicer recoil system (ie longer spring and heavier buffer) and they offer a continuos uniform cheekweld, which is nice.
Get an optic, and get a good one, with a good mount. Cant say that enough, and you will see it time and time again here, a $2000 AR with just BUIS, and then a $4000 AR with just BUIS, and then a few rich folks will have complete setups. even the budget builds have no optics. I keep a $100 optic around to go on new builds, but it gets replaced within 6 months for a high end optic and the cheap one moves to the next build for temporary duty...
Also a midlength gas system is lighter on the internal parts, and it allows you to add a longer rail down the line if you want to add more accessories.
I preach about midlengths because I had one at one time and really liked it, and when I bought my SHTF carbine, I got a carbine system rather than a midlength system and it is my only regret, but the price on my setup was way below market value so it was a steal, and the gun shots and runs great.
Have fun with it.