I am in the process of having a canopy built for my 72gal bow front, and, like you were, I'm now wrestling with the lighting issue. I know MH's are the fav. among hobbyst, but I'm wary of the heat, UV and load on my old house electrical wiring, not to mention the extra $$ to run them. Also, I am very UV sensative myself, and, from what I've been reading, surprizingly, so are many aquatic creatures sensitive to overload on UV. Are you using e-ballasts with those VHO's [icecap?]. I think I remember you posting that you were. You have any pics of your tank you can email me? I'd love to see the aquascaping setup you're describing.
I plan on going DSB too, and I know you've talked about it here on the BB, but, if you don't mind talking more about it, I'd appreciate some email correspondence from you.
My feeling is that 300+ watts of MH is going to be overpowering to my tank as well as my housing wiring, not to mention my budget! And, too, VHO gives your various bulb lighting options to play with, and I like that.
Any info would be appreciated.