I have the Tam 28-75 f2.8, kit lens, 50mm 1.8, 420 ex flash I'm thinking of taking just the Tam, and a new lens.( should i bother with the flash,50,kit lens? I'm thinking about getting either the Canon 17-40 f4L or the canon 10-22 ef-s lens. They are both the same price around 650, so i'm sorta on a toss up. Suggestions?