hi guys, this is my first post, my son has started me down the path of the AR platform, i used to be an ak guy, but!! my son showed me the light, my son will be leaving in maybe 6 weeks to join the millitary, not sure as to which branch, he has tenative planes for uav's in the army (smart kid huh!) in any event i seek to build my new weapon with his help, and to enjoy the first shooting with him as well before he leaves on his grand adventure. but i am hitting nothing but walls. difficult to find lowers (is stag good?) impossible to find the ubr stock!! impossible to find the beowulf upper!! i have had many weapons, and have always settled due to availibility. but because of my sons knowledge, and my desire to this right i seek your help. in all cases if i buy on availibility, than my son will be long gone, and my need to share this with him will also be gone until he returns. any and all help will be greatly appreciated