Ok right now I have 3 AR's. One 7.5" piston pistol, a .50 beowulf, and a 5.56 Noveske Afghan barreled/TR24 equipped, semi precision 10lb rifle. So now I'm in a dilemma. I want to build a lightweight AR, but at the same time, I also need something I can use to participate in 3 gun, be my go to gun for SHTF, as well as something I can take classes with. So basically it needs to be light, accurate, durable and reliable. No problem you say? Well I also want to do it without blowing my savings. I would like to do this under $1500 without optics if possible. I may be able to stretch it out a bit, but I want to limit myself for now. The most important aspect is the weight, as my faux noveske is reliable, accurate, and durable, but is simply too heavy to run around with.

If there is a prebuilt option, that would be ideal as my gunsmithing skills are somewhat elementary. I hear good things about JP rifles/uppers for 3 gunning, but I can't find anything about their weights, and I'm a tad skeptical about their ability to get roughed up in training classes. Please correct me if I'm wrong.

BCM 16" Lightweight topped with a 1-4x scope of your choice in a LaRue mount for 3-gun.  Remove the scope and install an Aimpoint Micro when you leave the range for HD duty.  TRX Extreme handguard for lightweight, accuracy, and versatility.

For a lower, I'd use a MOE or CTR stock.  

Easy.