The 7D has the crop factor which does help with wildlife they are also really cheap 2nd hand sub £500 so very good value. Only downside is over iso800 there is noise.
As for a lens I would highly recommend the Canon 70-300L, it is light and compact (relatively) great IQ and stunning IS for under £1000
There is also the Canon 1DMKiv. I got one as it was cheaper than a new 5Diii and it has x1.3 crop factor, it does 10fps if you need it, the battery lasts forever, it is properly waterproof, AF is superior to a 7D by far and more than enough to get anything I have pointed it at sharp 95% o