Thninking about planting My Tank

Here's the story.

I just got a pre-populated 40-50 gallon bowfront (haven't actually measured it but I'm guessing 46 gallons) prepopulated with fish. Being new, I already got advice for the fish in the noob forum.

I am thinking about planting the tank. One question I have, and have not found an answer for is How deep of a tank is to deep for planting? I know the depth of the watercolumn is extreemly important when dealing with other light sensitive organisms (like corals and anemones), so my assumption is that this is something I should consider.

Currently the tank has decrotive gravel and an undergravel filter. both of which will be replaced with a soil/sandbed, and I figured I would move on from there to lighting, then to CO2 then to plants. Anyway, that is the plan, but actual activity is a month or more away while I study the subject first.

I'll get the real dimensions and volume of the tank tonight and post that up here.

My initial though on lighting was 2 10k lights or one 10k and 1 50/50. I think that will mostly depend on the plants. Again, I may be way off-base as well. I'll do my research. A couple of 10k lights shouldn't brake the bank though.