JAG Precision are recommending the Troy battle axe grip from Madbull:
Check out how to upgrade your AR15 or XCR into a more compact PDW style platform with the MadBull Airsoft Troy Battle Axe Grips. Several colors and the motor option in the package you cannot go wrong with this setup.
Read more here: http://www.jagprecision.com/troy-battle-axe-grip-by-madbull-airsoft/
