man, I could have hooked you up with the sump you wanted and a peacock mantis! Too bad I never heard back from you, no worries though, hope you find what you're looking for. You should post your location in a post like this - I overlooked it because of that.
Amazon aquarium in Alameda can get one, usually about 25 there. Octopuses Garden in Berkeley has one now - they want 47, but I'm sure they would take less if you offered it, maybe 35 would be a guess. 6th Ave. gets peacocks sometimes, $20 when they do. And finally, both Tropical Paradise and Aquarium Concepts can order one for you. Good Luck.
Oh, also Everything Fishie has a beauty peacock right now. So many choices...