High powered driver for 10W and 45W LEDs
The best thing is to make 8 strings of a 14 V LED in series with a 9 V LED.  

The LT3496 can drive 3 strings at maximum 750 mA from an input voltage of 3V to 24 V. So you'll need three of those for 8 strings.  

  

The application needs more components than just the common series resistor, but the latter isn't very efficient; you need a few volts drop across them to get a good regulation, so that's at least 8 x 1.5 W loss.