rly nice pics.. but I once heard that a Canon lens is always better for a Canon Camera then a sigma lens or something else... not true?

Maybe it depends on the lens? Nah, I don't think it really matters... Sigma makes their lenses for canon, for nikon, etc... so I think it's fine.. I'm using a Tamron and a Sigma on my Canon

Actually from what I have read in some of those online reviews the Sigma 10-20 is somewhat better than Canon ef-s 10-22 lens and a bit cheaper too
I believe you should only buy Canon when you want those very high quality L series of lenses which are of course very expensive too lol.