Ya, I was thinking that would be the other option as well. Either 6 or 8 on top is great, and 4 or 6 on the bottom since it is so shallow. I run 6 (4 bulbs actinic/2 daylight) on my 29G tank and it can handle SPS corals fine.. so 8 would be for only the highesly light demanding corals in your tank if you go that many. Your display is also going to house the corals you want to frag isn't it? So you should have equal lighting conditions.. 6 up top with the depth of the tank, if you place the coral 1/2 way down in the tank would equal being in the frag tank under 4 bulbs I would think.
looking forward to it filled with expensive animals! 
it doesn't have to have good head pressure as it will rest behind the tank on the stand.