One more for t5's. Been reading a lot about lighting lately. T5's would be cheapest, however you won't get the shimmer. As A_Shea mentioned, you could get t5 fixtures with metal halides in them, but that would be expensive.
LEDs will give you the shimmer, but they're expensive as well. Also, I'm not sure if there's much available that puts out as much light as you'd need...
If you went with a DIY LED fixture, it would probably still be expensive, and also a lot of work. Here's a diy build that would give you an idea of what you'd need to do to build an LED fixture: 28 LED BUILD
If you went with LEDs you'd probably have to do this, but on a much larger scale. Of course, if you're not worried about money, you could probably find a pre-build LED fixture that is designed for plant growth.
Yes, you'll probably lose a lot of Co2 with a wet/dry. I haven't looked too much into fluidized filter beds, but from what I have read, that seems like it might be a good option. But, before you go that far, how is your wet/dry set up? Could it be converted to use standard bio media? The problem with wet/dry is too much water movement. You may be able to use standard bio-media fully submerged so as to cut down on water movement while still using the same equipment. All depends on how everything is set up, though.