I am just getting into photography as a hobby and purchased the Canon 60D with 18-135mm lens. I will be going to the Grand Canyon and would like a 2nd lens. I'm assuming a wide angle is the way to go, and also something I'll use a lot since I travel often. Any advice on whether I should invest in a Canon wide angle (any suggestions welcome) or Canon ultra wide zoom (EF 17-40 or EF-S 10-22)? I've already purchased a tripod, bag, extra battery, and UV/polarizing filters for the current lens. Any other equipment that I should consider prior to the Grand Canyon trip? Thanks for your expertise and suggestions!