Pump placement is something you will need to play with in order to get the most turbulent mix without blowing sand all over the place or directly at a piece to where it will peel the skin right off. Placing them in the corner is a good place to start, just make sure there are no dead spots, and your rock placement aids youi in doing this.......
If its going to be a SPS tank primarily, more flow is always recommended.....a number that helps describe how much flow you have, but doesn't do much than that(sort of the watts/gallon metric for flow), is how much turnover you have in your tank.....Its computed by (return pump exit at display in gph + all powerheads in display gph)/(gallons in display).....it gives others a gauge for how much flow you have. Most recommend about 30-40x turnover is minimum for a SPS tank, but that can go up to 90-100x for people on the high side. Keep that in mind. Most have opted for the high volume, lower velocity pumps such as the Seios and the Tunzes for better results.
As far as the lighting, 1 halide per 2 foot generally. If your tank is 6' long three would be perfect. Some of the people who have been around longer than I say they prefer the Actinics of VHO comparted to PCs due to coloration, so you are probably cool there.
Have you considered what K of bulb you want to run........If you like them superblue, you could just run the Halides running 20K and skip the other supplemental lighting, however 20K usually will have less PAR hence growth than say a 10K, so by staying with a 10-14K and using the VHOs, you can have the color and better growth....