Nah dude, you're not getting it. The VIKINGS were way more awesome than everybody else!!! They were totally badass dudes with beards and horned helmets and stuff who conquered things, and are on the covers of METAL ALBUMS and they were totally cool dudes who were all tolerant and like, ahead of their time and stuff, because that's the way cool people are! Never mind that most of the conquering they did were raids of defenseless settlements that couldn't resist them that involved plenty of rape, but it's cool because we can still live out our repressed white nerd power fantasies through them... VIKINGS!!!!!
Um... Wow...
Oh and yes, the Kazars were converts to Judaism.
Some of the Khazars were Jewish. Just as many were Tengri, Christian, and Muslim. They were rather cosmopolitan. The aristocracy represented a form of Judaism from the 8th Century, but not the culture as a whole (Unless you're going to spout off that 13th Tribe nonsense...).