Step One: The LED
The heart of the project are the 10W plate emitter LED's. I got these from Deal Extreme. I have also found them available from Aliexpress although I have not ordered this particular one. I have shopped from Deal Extreme for the past 4 years and have never had an issue.
The LED consists of nine 1 Watt Red, Green and Blue LED's with 3 of each color wired in series. The controller I am using runs off of 12 VDC so the first step was to determine the correct current limiting resistors for 12 Volts. Red LED's drop about 2.2 Volts when forward biased with green and blue 3.3 Volts or so. Each string needs about 330Ma to produce its rated power. I measured each string with a lab power supply at 350 ma of current. The red was 6.5 Volts, the Green 10 Volts and the Blue 10.5 Volts. I selected 22 Ohms for the red current limiting resistor and 5.6 Ohms for the Blue and Green. (Makes it a little simpler and easier to buy in quantity.) What power rating should I use? Power = Current squared times Resistance. So for the 22 Ohm resistor worst case we get P=(.350ma)2 X 22Ohms = 2.7W so a 3W resistor will work. The red will dissipate the most because it is the larger resistance.
The other thing to take into account is heat sinking the LED emitter. It must have a heat sink to keep its temperature down or the LED's will fail. I found some surplus 2”X1.75” heat sinks that are about 3/8” thick with a lot of little fins on them. They were originally for graphics cards. I figured they ought to be good enough so I bought a dozen of them. After an hour of use, the emitter plate was 50C and the heat sink warm to the touch so they are big enough.
Alternate source: http://www.aliexpress.com/item/1pc-High-Power-Super-Bright-Integrated-RGB-LED-Light-Bulb-Beads-10W-Lamp-Bulb-Free-Shipping/704083925.html
Alternate source: Mouser http://www.mouser.com/Passive-Components/Resistors/_/N-5g9n?Keyword=5.6+ohm&FS=True