60D is a nice option if you're going to be in more sports type situations.... it processes pictures marginally quicker as well as a faster shutter speed. The horizontal level is a nice feature, but one i've only used on my 7D just playing around, never seriously.
I believe the 60D may also have a better auto-focus? maybe i'm wrong, been a while since i've looked.
skip the 18-55 for sure, they lack in a lot of ways, the 75-300 is a nice shooter from about 100-200mm, but anything outside that, there's a lot of separation and drop in quality.
good luck with your shopping.