Where to buy brushed steel curtain rods?

Thank you all for commenting on my prevous curtain related post. Brushed steel seems to be a clear winner :)

But, as usual I've got more questions *shy*

What thickness rods would you recommend for the blockout curtain rod? I guess the sheer one doesn't matter so much as it will not be visible as much...

Also, any tips on where to buy brushed steel curtain rods?

B