Just a word of advice. The ergonomics/grip of the 550D is not substantial for most people. They get it cos its light and/or cheaper. However once you mount a heavier lens like the 18-200 or the 17-55 or any telephoto L lens, you'll wish you had a heavier body to compensate or counter the weight.
Personally i own the 500D and it feels unbalanced with my 18-200 even with grip. Yes if the price isnt a concern, i dont see why the 60D shouldnt be on your list =D