last year for christmas i bought myself a bushmaster 16" m4 type rifle that i love, but i also want to get an m16a1 replica rifle that has such features like a tri grip, a1 rear sight, a1 butt stock, a1 birdcage flash hider and tear drop forward assist. is it cheaper to build one or does some manufactures offer a complete rifle or kit? if available name a manufacture. thanks. i just love the look of the vietnam era m16s.