I wouldn't say you are way off, but you are pushing it.
The biggest problem you have is that tank is tall and you are using PC instead of halide or VHO which could penetrate it's depth.
I tend to think PCs are great for shallow tanks and not so great for deep ones.
Having PCs on a tall hex right now, I made a mountain of rock that comes within 6 inches of the surface. The stuff at the top has grown considerably, but the stuff (mushrooms) that are below the first 6 inches hasn't grown much at all.
You can do it, but you will be limted in what you do and how you can do it. That said, your plan is fine, but I don't think you should attempt 'light demanding' corals with that setup IMO.
Jenni
Goldfish Secrets eBook 
130 wat for 30 gal reef 
