Hello, I've been working with my kit for a while, and it has served me well for shooting most events. However, even with my 5D3, 550D and 70-200 f/2.8 IS II, I've found that it comes short when shooting big field sports such as soccer and football, especially as it gets darker. So I'm conflicted between choosing the 7D2 or Sigma 120-300mm f/2.8 Sport. So I'm thinking: 7D2 is half the cost of the Sigma. Paired with the 70-200, it has the same focal length range. It has much better ISO noise than the 550D, and only 1 stop's worth worse than the 5D3. It also has 10 fps burst and that wonderful AF system which are good for sports. Or I could get the 120-300 Sport from Sigma. It can be mounted on my crop body (550D) for a huge 192-480mm f/2.8 range. The obvious downside to this is that the lens would be mounted on a 550D for now. However, the Sigma has a f/2.8 aperture which mitigates some of the 550D's bad lowlight performance. It also costs twice as much as the 7D2. Eventually I'll try to work to get both of them, but which should I go for first?