Need to make a LED light to replace a halogen light

[cdrov]

Hi, there i need your help. I would like to construct a LED light in order to replace my older 50W spot. I am using this spot on a Video Camera while i shoot ceremonies.

I have tried several leds and arrays but i have not managed to have the spread and the power of the old one.

My latest efforts where P4 Leds from Dealextreme but what next?

What is the Driver? What Battery? Cooling? At the moment i am using 7,2 Lion Battery with 2 p4's in series but i am not happy yet?

Any help or suggestions would be appreciate. Thank you all