They are super light and airy (hence their popularity in the desert) that said I don't wear it all around the head like the how to vids. When I wear one I simply wrap it around the neck a few times like a neck collar.
It works beautifully. Also in the dead of summer you can get it wet and it'll keep you super cool. I do this for yardwork and wear it on my head like a sandana. I'll try to dig up a pic.
As for where to get them, shopping around is your best bet for price. I've always stuck with Brigade Quartermaster
Or you could get the "real" thing cheap: https://www.amazon.com/Shemagh-Kafiya.../dp/B001TP237I
I have several of those^ in red and black that are identical that I brought back from Afghan and Iraq. Hope this helps.