I would just run the 60" 80W bulbs on IceCap ballasts and keep them centered on the tank. You can put the low light corals at the sides of the tank, and you still get good light coverage as it spreads out. With this arrangement you have fewer ballasts, fewer end caps, and you can use reefgeek 60" reflectors all add up to less initial dollars. and every year you spend alot less on lamp replacement. all you are giving up is placing any light loving corals on the bottom at the ends of the tank.
Do the cost comparison in may be worth it, thats what I am doing!