So i finally decided to go for it and ordered up the supplies to do an LED retro on my 12gal nano-dx.
Parts List:6x White Cree Q5 XR-E ($6 each @ ETGtech.com)
6x Royal Blue Cree® XR-E (($6 each @ ETGtech.com)
2x 1000mA Constant Current Output, External Dimming w/ pot. ($19.99 @ ledsupply.com)
1x 24V-6.4A supply ($14.95 @ MPJA)
1x 24V-3.2A ($17.99, marked as "70W universal laptop power supply" from Geeks.com)
10 x 5.375 inch heatsink ($20 @ heatsinkusa.com)
Total Cost: (not including shipping)$145
Side notes/ tips before the pics:-If you want to save some $$ go with etg tech on the lights they sold me the q5 for $6 when led supply wanted $9 each, all you have to do is call them, they were really nice and knew exactly what i wanted.
-USE A DRILL PRESS, the press i had would not take the drill bit the 4-40 tap needed, needless to say i snapped 4 drill bits trying to do it by hand

and it took me about 3.5hrs to drill....
-If you can find a universal laptop power supply at a local frys or the like you can save shipping from MPJA, and have an already packaged unit. All you gotta do is cut the connector off and there should be two wires, red/black, then just hook the buckpuck to it and your done.
-Last but not least enjoy the process! I had a blast building the fixture and it looks great.
Now the pics:
Buckpuck from led supply w/ pot

LEDS from ETG tech.

We found these little pink boxes at Michale's

They worked really well for packing all the wires.

Top side wtih pots. mounted.

Initial layout for the leds, the wife laid them out while i was off studying for school.

The hand drilled nightmare. As you can see there are a few drill bits and a tap broken off in there.

All drilled and tapped and mounted with our bracket, we found at home depot for .50 and bent to fit.

All the led soldered down in series.

Last but not least, TADA all the lights powered up and looking good.
It sorta hard to tell but the lights were laid out like this::
White,
Blue, Blue, White
Blue, White, White,
BlueWhite,
Blue, Blue, White

I dont have any in tank pics as we got home too late last night to turn it on. Ill post some today when i get home. If you have any questions or i made any mistakes, just shoot me a PM.
I haven't added the fans yet i need one more power supply, that ill go out and buy today. Im going to mount them shooting across rather then down onto it. It should cool down the heat sink more then the top down fans. So for now i have my large floor fan mounted on the side blowing onto it.
It was fun and for about the same cost as a HQI solution for a cube, i would pick the led any day.
http://www.nano-reef.com/forums/index.php?showtopic=209096