As far as the jbj lighting, theres lots of ppl here that use it, and you could even do a search for it and find an almost identical post.
As for the mantis, isolate it to one rock, and take that rock back to the LFS. Please dont kill it. Lots of ppl want to keep a dedicated Mantis tank, and cant find specimens, because ppl always kill them off. You wouldnt kill other inverts just becasue they hitchhiked would you? Their beautiful, intriging creatures, with very strange and interesting habits and lifestyles. If you have a 10 gallon your not using, drop the rock in there and check out this site on how to care them.
http://www.blueboard.com/mantis/
Hes not the boogie man. Just doing his job in the ecosystem.