As I'd considered similar things this video fascinated me. Start to finish with parts list. Quite a few possibilities here for more powerful LEDs and battery set ups. Not to mention small water cooled systems with water proof fans for outdoor all weather use.
http://www.youtube.com/watch?v=c--5c3Egv4E&sns=em
If dont like links just go to youtube and search DIY Perks Sun Blaster.
http://www.youtube.com/watch?v=c--5c3Egv4E&sns=em
If dont like links just go to youtube and search DIY Perks Sun Blaster.