Yeah, Luxeon V from Led4Power.com is available in 4000K. Kaidomain has it in 5000K and 6500K. At high power, it is slightly brighter than SST-40, and it won't die past 9 Amps if you abuse it (so, acceptable with FET).

That said, it WILL draw a crapton of current with a FET because its Vf is so low.