There's also a thread up at the very top of this main thread that says "I want a heavy/heady/mixed kava" and it's nothing but people asking questions like this. You should probably look through that, you'll probably get some awesome advice there too!
I love browsing the threads at the top cause there's just much info. Good luck!!
Edit to add: I want the exact same type of kava you want, so if you find anything perfect, let me know!! I drank some KWK Boronguru last night, and I slept like an exhausted baby. I usually wake up a few times during the night, but last night was straight sleep. My head hit the pillow, next thing was the alarm going off. And my muscles are still relaxed this morning. Highly recommend!