I bought the t2i that came with the standard 18-55mm f/3.5-5.6 kit lens, and also purchased the 55-250mm f/4.0-5.6 lens. Helped a friend photograph a wedding this weekend and was not impressed with either lens, especially in low light and action shots. Got lots of blurry and dark pictures. Any recs on a better lens? I prefer to stick to one great overall lens so I don't have to switch between the two. And any recs on a good flash?