Hi Lee,
Doing some research on LED's vs. fluorescent, I came across this really useful article, particularly in regards to fluorescent vs HPS vs MH (and a few more - but not so much on LED's). There are some good comparison charts towards the end of the article.
http://www.greenmanspage.com/guides/lighting.html
BTW, I disagree somewhat with Hermitian's statements that one "must" have 6500 K lights (although they are desirable for seed starting and vegetative growth) or that the lights must be 1 meter above the plants (that might apply for his particular scenario, but I think that most of us have fluorescent lights MUCH closer to the plants - especially seedlings - than 1 meter!).
Anne