DIY LED lights

[ALToronto]

Has anyone here taken a bunch of individual diodes and connected them to make a light fixture? I'm planning on doing just that, for a totally custom-shape, thin profile fixture.

As much as I love Ray's lights, I'm making a plant stand for seedlings where neither screw-in lightbulbs, nor 4' tubes, will fit. So I've placed an inquiry with a Chinese (what else!) LED manufacturer for some high-power (3 W) diodes in daylight white, bright white, red and blue. I'm waiting to hear back on pricing, but I get the feeling that these will be by far the least expensive solution per lumen output.

I plan to combine the different colours into strips and/or panels of about 40-50 W total power input. If anyone has played with these, I would appreciate some advice. I plan to order the following:

6500 - 8000K, white, 3W
5000K, white, 3W
430 nm blue, 1W
660 nm red, 1W
50 W drivers

Am I on the right track? Have I missed anything?