Welcome from Indiana brother Michael,doesn't look like thier is a charging handel on the rear of upper reciever.You could do a couple of things' 1- get some styrofoam about 1 1/2" thick and shape what you need and tape it on or 2- this : http://www.midwayusa.com/product/643824/bell-and-carlson-cvt-adjustable-cheek-rest-ar-15-a2-buttstock-aluminum-and-kydex-black the MapPul precision stock you are referring to is nice with lots of adjustment but it's also heavy.Just so you know.Look up cheekrisers for A2 stock and there are many options.As for changing muzzel device mine are done for less than $40.00.I recently have a barrel cut down,threaded and had a comp welded on for $110.00.For the price of the tools needed ,how many devices to you plan on changing in the future to make it worth while?Just my 2 mags.