Next year I will be taking a short trip overseas and am hoping for some advice regarding lenses. I currently have a 400D with the standard twin lens kit but I was thinking of getting a superzoom as I don't want to keep changing lenses or take too much with me. I am getting $300 as a Christmas gift to put towards my purchase but anything above that will come out of my travel funds which I am hoping to minimise. I have found 3 lenses which fall in or around my budget and was hoping for opinions on these or other suggestions. The ones I have found are Canon EF-S 18-135mm F3.5-5.6IS,
Sigma 18-200mm F3.5-6.3 OS and Tamron 18-200mm F3.5-6.3XR DI II.
I will be going to California and Las Vegas and hope to see the Grand Canyon and Alcatraz amongst other things so I need to be prepared for whatever photo opportunities arise.