I wish I would have seen this sooner; I know someone who has a reef aquarium and they yanked out a mantis shrimp, that was a really nicely colored clubber btw, tossed it on the floor and stomped on it angrily. I love these creatures, and apparently some people consider them pests! He offered it to me first, and unfortunately I couldn't house it because I've only got FW tanks ATM.
Normally your local fish store can sell them to you for relatively cheap, or can make a phone call or two to get you what you need.
This site doesn't list if it is a spearer or a clubber, but I'm sure you can call them:
I have a 2"er thats decently colored (has the peacock markings on the clud). Looking to get $20 for him. Probably another $20 to ship, but don't quote me on that.