At the start, I used my EOS 5D MKII and the Russian Zenitar 16mm fish eye. After the 300 mm I switched to my EOS 7D to make use of the crop factor which gave me an effective 420 mm focal length.
Since doing this test, I have sold my old 300mm and my 70 - 200 zoom. They've been replaced by the Canon EF 100 - 400L zoom so I may have to repeat it again!
Thanks for reading.