I've got an RRS MC-34
and MH-02 Pro head
, love them both and they work great. Plenty of height, plenty strong enough. I carry it on my belt when hiking, with my 1D X + 600 II slung over my shoulder on a Blackrapid strap.
If you only plan to use with the 600 II, the MH-01 head may be better (the MH-02 allows 90° rotation to mount a camera plate instead of a collared lens on the fly, with the MH-01 you need an allen key to switch orientation). Either head can have a screw clamp or a lever release, I opted for the screw clamp to aviod the risk of opening the lever clamp while carrying the lens mountd on the monopod resting on my shoulder.
The monopod + head combo fits perfectly in their TQB-64 bag.