You can't download Safari for any version of Mac OS X. If you want to reinstall it, you can do so from the Snow Leopard installation disc. But Safari isn't the problem, so reinstalling it will not solve anything; the problem will still be there.
It's better for you to describe your problem in detail so we can address the problem here.
Klaus1, that's incorrect. The Safari downloads are updates, not a full package. Also, the OP is using Snow Leopard, and the Safari updates are for Tiger and Leopard, not Snow Leopard. The only place to reinstall Safari for Snow Leopard is the installation disc, as I mentioned.