Hmmm...interesting question. I've only heard it used as a noun, like you say, "I'm off to get some kip now" etc....
However, one might also be creative and break the laws of convention by saying "I am kipping right now". Doh....no, not likely if you are asleep...."She is kipping right now". That could work :-) Not the usual done thing, but hey, who cares?!