Yup I remember the ballast conversation. My concern would be with the depth of the water column. Remember at 19" your lighting loses 50% of it's intensity, and for most 400w bulbs that means most the red end of the spectrum will be just about nonexistant at 24" and below.

Bulb choice with enough PAR will be critical to reach the deeper depths.

On the other hand if you are planning on nothing but softies and some LPS you may be okay, but 2x400 is barely going to net you about 3-4w/gallon total. That's with the majority of the coral at midline or above in your tank. On the other hand 2x1000w halides would be fantastic, though not practical for heat or the 'lectric bill.

The nice thing is your tank is 30" deep, so that leaves you with a lot of options as far as lamp placement goes. I'd think 3x400w (or maybe 4x400w) would yeild far better results.

The PC's for supplements have been working out well for us.... though I'm going to increase ours up from 4x65wto at least 6x65w, probably just jump up to 8x65w and mix in some Actinic 03 with the 460nm tubes this time.

They really need to come up with something between 400w and 1000w for halide lighting purposes, maybe some 750's or something. Then again maybe it's better if they don't, or I'd have to upgrade yet again.