OK, so I stumbled into this for a song and maybe 1/2 of a dance. But now I have no idea where to go from here. I've never even looked at building one. I work on old rifles, not this newfangled, "modern" stuff. LOL I'd like to build it out right, but I'm also on a budget for this. I want a rifle configuration with an 18" barrel and full length hand guard. Trying to decide between .223 Wylde or 762x39. First goal is to get this lower complete. What would be a good parts kit to get that's cost effective but decent quality? After that what do I look for in an upper and barrel? Thanks for the help.