I am still up in the air about building from parts or buying complete. I have narrowed my search down to what I want......ideally something close or identical to a Rock River Arms Elite CAR A4. Because of where I live (New York State), and the AWB (still in effect:roll: ) there are certain options that are unavailable (collapsable stock, bayonet lug, etc.). I really don't care about most of the options accept the 6 position stock, which I really want. I am now looking into building an AR with Rock River parts the way I want it. My questions are.....how difficult is it to buy and assemble (how technical and tools required)? If I use Rock River parts, is there any reason that the final fit (quality) would be less than that of factory assembled complete AR? Will my final cost be less than buying a complete rifle? Should I consider mix and match from different manufacturers, or would the quality suffer? Thanks for any input, this will be my first AR and I'm pretty excited.