My first DSLR kit was the 50D and the 100-400 (and the 28-135 kit lens). I wanted to take photos of the large Florida birds after we moved here. The 7D was introduced later and I looked, read reviews and decided it was good for me. Saved and got one. Liked it so much that I wanted a second to replace my 50D. Discovered the CLP and ordred my second.
The autofocus alone made this a superior camera to the 50D for BIF. I had been shooting the 50D tripod mounted on a 500mm and the 7D handheld on my 100-400mm but the second 7D made the whole operation better.
Get the 7D, after the first month or so you won't regret it
The autofocus will take some time to really master but the 7D is worth it.