[D to the P]

you can build your own sump yeah, but if it is hidden than why not just go for a big ol' Rubbermaid tub, not the containers that are just large I mean an actual large plastic tub with built in drain hole. I don't think they are that expensive, and than you wouldn't have to worry about buying acrylic and trying to make it look nice and be functional. Your best bet for a skimmer is to get the biggest one that you can afford, but I would aim for something that is rated for twice the size of your tank, I like the ASM brand of skimmers, many others like the octopus's. The lights will have to be decided after you figure out what kind of corals you want to keep. I would recommend looking into T5 lighting because they are really functional and can go over top of any corals as long as you have a good system with enough bulbs. Good luck, and keep us posted.