i knit three of the russian winter hats, with completely different yarns, the first one i used straights because i didn't have a circular needle, and it was really hard, but it can be done. for the other two i went out and bought a circular needle.
for the yarn choices, because of the way the hat is formed, you can use pretty much anything, i think. i made one with lamb's pride bulky, one with lamb's pride worsted, and one with a weird yarn my mom gave me that's somewhere in between those two weights. without the eyelash yarn, it's a really cute simple bonnet. i think it's way more flattering on me than round hats, plus it covers my ears.