If this is going to be a reef, definately go w/the large lumenarc III reflectors. They are the best according to Sanjay, and are for large tanks. They measure 19.5X19.5 by 8" tall. Best of all you can get away w/3 400watters on an 8ft tank because they are made to hang high, which will also be an advantage to lower heat, and if you use electronic ballasts, you'll save some on the electric bill. I'm going to put 3 on my 180 in the next month or so. They only run 120bucks from Lumenarclighing.com and they even have package deals on ballasts and bulbs.
I'd also use a Sequence Hammerhead to run a closed loop, or 2 sequence darts on a parallel closed loop, and a single sequence dart as a return pump. Make sure you use 1 1/2" plumbing on the closed loop if you use these pumps to get the max flow. You'll need it on this big of a tank. They are super quiet and efficent. Best of all they are American made!!!
Good luck.