Mantis prefer frozen meaty foods or live food. I feed mine frozen krill, frozen clam, and frozen formula 1 cubes (small part of a cube). I just randomly pick one of these to feed him every other day or so. I also keep a hand full of snails and hermits in the tank with him so if he gets hungry he can help himself to some snacks but for the most part he leaves them alone b/c I keep him well fed.
As for lighting, filtration and such go the same thing that you would use for a fish only setup will do. I would use a titanium heater and avoid glass thermometers however. Other than that it's important to provide a deep substrate for burrowing and live rock as well as small piece of rubble for building materials. You may also want to put a power head in the tank to help move water.
-David