I'm trying to decide on what lenses to get. I have an XSi with the kit lens. I'm also borrowing a Sigma 17-70mm lens from a friend that I seem to like and might just buy it from him. So below are 3 options that I'm trying to choose from.
1. Keep 18-55mm IS and buy a 55-250mm IS lens.
2. Buy the 17-70mm from the friend and buy the Canon 70-300mm (I was thinking about the 70-200mm but it might not be long enough to shoot wild life).
3. Sell the kit lens and buy Canon 18-200mm (or perhaps something equivalent from a third party company).
I've been wanting a telephoto lens but really don't know what I should buy. Any advice/help is greatly appreciated!