Business and hobby

For a beginner I do not see a reason to go for a bigger and heavier "more advanced" tool, so out of these 2 definitely get the 600D. In fact I would strongly recommend to take a look at other cheaper options

600D is enough is has basically all the features that 7D has and the 7D does not have a flipout screen so you can capture things in more interesting angles. Only buy the 7D if you are truly interested in doing sport photography as it has a very fast burst mode, but for other kinds of photography that is pretty useless to use.

Cannon EOS 7D

because have many advantages than EOS 600D