This is really basic but could you clarify this for me? Some controllers will provide both data and power to the RGBs while some others will only provide data and power must be fed straight to the RGB lights from the power supply? If correct, what should I consider to help me decide which type of controller is better suited for me? I am right at the beginning playing with RGB lights; waiting for 2 strings of 50 RGBs 2811 5V to arrive from Ray and need to select the controller and power supply. Help and advice appreciated!