50d for that budget, albeit its due to be superseded before long, so either hold out for its replacement or buy up a cheaper 50d after its been replaced.
Personally i would switch to Nikon whilst you don't have too much kit.
And thats not even a joke.
Laura, No idea if your local or not, but if your heading up to BTCC @ Brands this weekend then let me know and you can have a go with the 50d.
I jumped from 350D to 40D and that was immensely nicer to use. If you don't want the bells and whistles of video, get the 50D over the probably soon be announced and way more expensive 60D.
You can set the 50D up so you can change the settings on the screen too mate
Mines setup so if I press the button in the middle of the jog dial the settings come up on screen - then I can move around using the little joystick and change the settings using the jog dial
I like the dedicated auto-focus button too - really handy