Ok, First of all I appreciate you guys taking the time to read this. I need some help with an AR-15. I am planning on buying the Smith and Wesson M&P15R which shoots the 5.45x39 caliber. I found a good deal on a new factory one. $750 Delievered.( with LE discount). I don't know anything about the AR system but very willing to learn. I had the AK47 and now own the Arsenal SGL31/ 5.45x39/I always have been an AK guy.Always will be What I need help on: I need to know where a top quality gas piston conversion kit can be found for the AR15. I need someone in Oregon that can help me install it.(the gas piston kit) I need someone that does trigger jobs on AR15s. (need a smooth trigger) I know that many say that you dont need the gas piston kit and its a solution for a non-problem. I also know you loose about .5MOA . Sorry. I'm already decided about this part. P.S - Please remember I dont know anything about AR15's so details would be helpful. Thank you very much.