A fairly simple and cost-effective way to make your shoulder rig.
This mounting method will fit both 15mm and 19mm rods, just make sure whichever barrel mount adaptor you buy can accomodate your size. The adaptors, the picatinny riser, and the grip pod all normally run around $10-$20 per piece. Not a bad deal even when you compare it to a similar rig like Redrock microShouldemount. There are also 90 degree picatinny adaptors so you don't need to purchase a handle like the x that I have.
Only downside to this is searching fot the right adaptor that suits your need. You'll have to do a little bit of looking around or grab a friend who loves modern firearms and show you around:-)
Couple more pictures at: http://gtsai.com/index.php/component...nny-should-rig