Current Camera, XSi/450D I'm starting to do research on building my lens collection. two lens I want to buy are an ultra wide and a good portrait lens. For the wide angle lens I plan on going with either a canon 10-22 700ish or sigma 10-20 450ish However for portrait, I'm lost. Trying to keep the budget under $1000 for a portrait lens, what would be a good lens to look into? I would like the option to upgrade my body and still use the lens down the road on a camera like the 40D. Thanks for any input.