I will take that into account Frank. My reasons for wanting one is SHTF, coons, and b/c I miss my military days. Among others.
Well here is my suggestion.
LPK pick whichever suits your fancy. Or go
here and customize your own[/url] when they are in stock. Personally i prefer the magpul trigger guards as they fill in that annoying gap. I also upgrade the triggers. The ALG ACT is the best option for sub $100. I suggest geiselle if ypu want to spend more than that.
For stocks just pick what you like but watch cheek weld if you plan on putting on more than open sights or a red dot.
Then you have a nice all all purpose lower to put any upper on. Pick up uppers as funds allow and as you want to change set ups. You can also pick up lowers and assemble them as funds allow.
As to uppers. Unless you really want it to HAVE a carry handle go flattop. I dont think 14.5 inch barrels are worth the permanently attached muzzle device.
Twist rate. 1/9 is as slow as i reccomend. It may or may not shoot 69 grain bullets but will shoot any lighter weights. I prefer 1/7 twist because I can shoot as heavy as they make and may lose some accuracy with 55 grain m193 style ammo. I cannot go lighter than that because the velocity and spin rate actuslly over stabilizes them and may blow the thin varmint jackets right off. Keep in mind the ATF shenanigans and ammo availability and pricing.
Chambers. .223 can only shoot .223 safely. 5.56 can shoot either but is generally not as accurate on match type ammo. Wylde is 5.56 safe but has some characteristics of the .223 chambering to increase accuracy and is generally only found on precision influenced barrels.
Metal GI mags can be found for less than $10 with magpul followers. Magpul plastic mags can be found in the teens.
Beyond that ask away.