I just bought a nearly new one from Aperture, bit reckless as I've still got my Canon system gear
Those canon lenses work brilliantly with the Metabones convertors on the mark ii esp the speed ones.
If you can live with the size and weight you can end up with some stunning fast lenses on it.
You would get a 105-420 lens so effective 210-840 on the mark ii.
Would also become a f3.5 to f5 as well I think.
Must be somebody put there using on on a meta bones
Great shots. Looks like you are enjoying your new beast?