Hi some good advice given.. . I would like to know what sort of images you are hoping to use the new gear for?  Rich brings up a point I have also often mentioned regarding future Camera upgrades, as you may end up as I have done having to get rid of perfectly good lens that will not work.. 

Your max amount you can spend is also worth knowing? 

I have not tried the 17-70 lens I  have the 17-40 and   24-70 L both are superb but of the two you chose I would go for the Canon
 
The Sigma 10-20 is a cracker for the money as you can see by all reviews I have read.. And in my view is probably better than the Canon equal of it.. 

The 50mm Macro I would give both a miss!! You would be better with any of the 90-105mm Macro range  from Sigma 105mm  Tamron 90mm or the 100mm Canon my own choice.. These will allow you to be further away.. And if you need 50mm go for the Canon 1.8

Danny O'Byrne  http://www.digitalartzone.co.uk/

"All the technique in the world doesn't compensate for the inability to notice" Eliott Erwitt