I can recommend G&P M203 Military Version + G&P handguard. I have it mounted on CA M15A2 rifle and although some slight modification to launcher mounts was required, it is rock solid. If money is no concern to you, get G&P quadrant sight and you will get nice complete set :-)
See
http://www.wargames.sk/modules/coppe...2/Dsc00055.jpg :xmas: