Hope the tank turns out good! Just remember to try some easier fish first before getting the more challenging fish like festivums. They go well with angelfish but need clean water. For the lights, you could always go to Home Depot and see what they have.
You want around 250 watts of light if you want to keep a large variety of plants. In the background, I would put Echinodurus (swordplants) and Vallisneria. In the mid ground, I would put many pieces of driftwood and rocks. Just remember that some rocks harden the water, and angelfish like the water soft. As for plants in the mid ground, I would put Bolbitis and mosses on the wood and rocks. For the space that isn't occupied by rocks or wood, put in larger cryptocorynes and anubias. Special and unique plants also go in the mid-ground. What you keep in the for-ground depends on the light. To play it safe, I would put some lower growing cryptocorynes. If you want crypts to grow low, you'll have to plant them with enough space to themselves. As for slate, you could put some pieces on the sides of the tank. If you plant a lot of plants at first, cycling the tank is much easier. Just let the snails multiply and they cycle the tank for you. And when you put in the cichlids, they eat the snails.