Marbled Salamander care?

Ok so i was planning on buying a pair of marbled salamanders. The cage i was thinking of making for them was a 10 gallon with a rock outcrop kinda thing with moss growing on it then a sectoin of gravel/pebble water area. I heard the tactic about blending up moss and adding ermilk/beer and spreading the past on rock to grow. I was planning on doing that on the rock. Should i add a dirt section or anything? im going to put sticks and stuff just was wondering about the rest. Also what would be a good diet for them? Earthworms? Crickets? I know there heat and lighting and everything so im good on that.