Is it easier/cheaper and what will be the price difference and quality difference to get a used polytech, springfield, or norinco m14/m1a and then get a new stock and barrel (i want a mcmillian family stock and a krieger stainless barrel) and get everything replaced with usgi parts. or just get a full custom build SEI (smith enterprise) with a lrb reciever, usgi parts, and a mcmillian stock and kreiger barrel? can mcmillian stocks be pillar or have a bedding block installed?