Skimmer is a must. buy one a little over rated for your tank just incase you upgrade save some $$$$
Lighting
live sand=LS
live sand=LR
is your sump a fuge where you can house some substrate (sand) and LR with some cheato algea. with a light over it.
Heres a good link to setting up a tank
Vivid Aquariums Tropical Fish Store in Los Angeles - Saltwater Aquarium Tips - Do's and Don'ts Vivid Aquariums Tropical Fish Store in Los Angeles - Aquarium Filter Systems Explained - Sample Systems / Recommended Products 