What are the pros/cons between the Sony 70-400 with converter or the Canon 70-300 with converters.
The Sony 70-400 is a very good lens, although it is heavy. On the A6000 it will probably feel a bit off balance, especially with the LA-EA4, but it will work very well and I assume you know that it will be a 105-600mm. The Canon 70-300 with converters are an unknown quantity on this forum.
Sony A7, A850, A77, A700 || Sony>> 70-300G, 28-75 f2.8 SAM, 16-80CZ, 50 f1.4, FE 28-70 OSS, FE 24-70CZ f4 OSS, LA-EA4 || Minolta>> 300 f4 G HS, 200 f2.8 G HS, 100 f2.8 (D) Macro, 50 f1.7, 28 f2.8, 28-135 f4-4.5, 70-210 f4, 500 f8 Reflex, TC x 1.4 HS, TC x 2 HS. || Sigma 21-35 f3.5-4.2. || Tamron SP 24-135.