Have you thought about...
I'm a Canon fan, have been since the mid 70s and film cameras.
Either of the Canon cameras you suggest will be very satisfying - the 100D being MUCH smaller and lighter than the others but still taking EOS lenses. The 100D is relatively new and so doesn't yet have a track record of reliability, etc, while the 700D is the latest in a long line of full size starter DSLRs, whose quality and reliability is excellent.
I think, though, that the 700D may be pushing your budget a little. Have you thought about its immediate predecessor, the 650D or the one before that, the 600D. Here in Australia (never cheap for this stuff!) there is about $50-$150 difference in price for essentially the same camera, less a few bells and whistles. Stock in the stores is limited, especially for the 600D but it might be worth pulling up a feature comparison chart from Canon or one of the photo magazines (where you can compare the Nikons also) and see whether the extra features on the newer models are useful to you.
General advice holds here - get a body that meets your needs and focus any additional cash on the lenses.