Bitters: what should I buy next?

I have:PeychaudsAngosturaOrange angosturaLimeCherry VanillaBut I feel like I'm lacking.I'll probably order from this shop, and I'm open to suggestions!Right now I'm thinking:Black walnutSome kind of chocolateCeleryGrapefruitCherry cedarUmame (cause damn, that sounds weird and fun)Maybe one or two of the sample packs for oddball things like lavender.Also, this sub is a bad influence. Just sayin'. http://www.reddit.com/r/cocktails/comments/3eyqq4/bitters_what_should_i_buy_next/