The OS 160 swings an APC 18x6W prop with ease,which produces loads of torque and has about 18 pounds thrust or so.The Moki will pull just a bit harder and this prop should work equally well,if wanting to have a lower airspeed with agressive bottom end pull.A Xoar 18x6 may work too and is lighter.I'd buy one of each as they will probably give the best performance.
Try them and good luck