OK. that was it. I think you see all these drivers are basically very similar. Since designing is a part of your education, I would recommend chips from national semi or linear tech, simply because you have a tool to simulate your circuit with the chip. You can learn a lot by checking and poking signal here and there. Many of those signal are hard to measure even with good oscilloscope. Once you understand one chip, you will understand rest of them easily. Designing proper value of parts need some calculations. Write down all the equations you see from datasheets. Later you will also find all those equations are same regardless of manufactures. Start from a reference design such as evaluation kit of a chip. PCB design of switching power is also very important. Careful on the SW - diode - GND (input capacitor) which need to be short length. You want to have big GND pour bottom of those switching circuit to minimize EMI. Thermal vias around the chip is also critical. If you don't pay for your PCB, 4 layer PCB is also good idea. For current sensing resistor, check Kelvin trace. That's what I can think of right now. I hope that helps little.
Switching plans again. I found this beauty of an LED driver:http://www.newark.com/linear-technology/lt3496ife-pbf/ic-led-drvr-tssop28/dp/07P8434Three individual 750mA PWM outputs. I will construct one PCB per light, and then use a terminal block to split the PWM signal from the Arduino. That way, If the lighting array needs to be expanded you can simply add another board and wire it up. I'll also be using 30W RGB LEDs, they take 28-33V in, so I will use a +36V PSU. Thoughts?