I came off of Phenibut using Mahakea, and it worked really well for me, but that was more for anti-anxiety than sedation, specifically... I haven't tried the "hanky panky" yet, but thinking about ordering some. Not sure though, I like the headier kavas... don't usually enjoy being couch-locked...
Your restlessness might have come from mixing kava with coffee... sometimes it does that to me, if I have too much coffee, the kava gets a little territorial about it, if that makes sense...