Options with lights.. what should I do

[BCOrchidGuy]

Okay, I've got 2 48in MH units now.. yeah, so I've got 4 175 watt ballasts and all the hardware. I've also got a 400 watt MH and all the hardware. I'm considering using the 400 at one end of my 90 gallon tank and keeping SPS there, and putting a 175 watt at the other end and keeping softies there. Has anyone tried this? I was thinking of having 400watt 20,000k radium and a 175 watt AB. I'm just wondering if it will look super odd or not as bad as I think.

I could just go to a longer tank and run 3 175s on it but, I'd like to keep bulb replacement costs to a minimum. I'd even consider getting rid of some of the stuff and going with two 250 watt MHs but bulb replacement would be the same as going with 3 175s (or within $30). Would 175s really be okay for Acopora?

Doug