Jeremy,
I used my PAR meter on a twin tube 36" twin flouro tube light set using 2 Verilux 30 watt tubes.
I got max readings of 175 about 3-4" from the tubes...
I know Tom just posted some info on PAR readings at a recent show, and they were only 35-150 micromoles from bottom to top....
Based on this, I would think anything better than described above would work fine.
I had 2 of these tanks, and would not recommend a pendant due to the length of the tank. My HQI cause dark tank ends and corners. I would say a couple t5 at 30 watt eac would be plenty. The tank is wide enough to double that if you want, or use 2 fixtures. You can always remove a bulb if need be to experiment, and you can always add it back in.
Max 2wpg if they are only 4" above the tank. I really don't think you will need more than this.
I used the above lights over the breeders and was able to get good growth. These were not high tech though..
IMO, If your c02 and fertilizers are in good supply, light is good, and good circulation/filtration, I think you will find you do not need as much light as we currently think.
I think that is what Tom is suggesting.....I think we tend to use more light than we really need, even for 'high light' plants, or high tech tanks.
The tank he showed has HC and readings were 50-60 on the substrate......and that tank is more than 40 gallons.
I would also suggest ADA as a substrate if you haven't already made this decision. This will help a lot I think for planted tanks, esp high tech with c02. I am going to try it soon in a new tank.......
Hope this helps.