If you're starting on the hobby level, something is better then nothing. The shutter is fast enough you could capture something thats quickly moving but because the burst rate is low. (3.5 fps) you have to be on point to get a good picture. The len's are where you really want to invest the money. You want something with f 2.8 aperture if its a zoom lens and something with a good reach. A 70-200 F2.8 / 50-150 F2.8 / 80-200 F2.8 , something with that kind of reach.
Honestly , if youre just starting out, use the 450D and a 55-250 kit zoom and see how you like it.
If money is not a major concern, Get a 7D or 70D. On the canon website they are about $700-800 refurbished. A 70-200 F 2.8 will set you back anywhere from 600-2500 depending on brand and used vs new.
If you look at other photographers at the track, those guys will be rocking a similar set up.
