if watts and lumens cant judge the light then how do u know how many lights u need to grow a plant......
That is the paradox... the answer is there is no simple way to go to websites that sell lights and see which one is the best - marketing is stuck in the lumens/watts mentality and this will not change until consumers become more educated...
To judge lights, first stop looking at it as a "light".
Instead, see it as a device that converts raw electric energy into colored light radiation. So the way to judge is how much of the incoming watts convert into usable radiation of the color you need.
Second, get a basic idea of the "inverse square law". This describes how radiation diminishes with distance. Basically at one foot you get full power, at two feet you have 1/4 the power, 3 feet 1/9th and so on.
The only problem with LED so far as I can tell is that they do not have a lot of initial power - past 1-2 feet they will not work as a primary light. However, with only two feet of clearance, you're perfect for LED. Then you add one or two daylight CFLs to cover yellow/green. Why? because beta-carotene, phycoerythrin, phycocyanin are secondary plant pigments that use this spectrum instead of red/blue. However, they are much less abundant than chlorophyll, the primary facility of photosynthesis, and consumer of red/blue light.
The LEDs will solve your heat problem and provide optimal growth... Frankly I can't see more than 1x100watt cfl or 2x65 watt cfl unless you remove the ballasts, in which case you would still be pushing the heat limits. But think with that 100watt CFL, you are only producing something like 10watts of blue, 5 red - the secondary pigments use some portion of the leftover green/yellow energy, and the rest is wasted and just makes your plants *look* pretty green to your eyes. Plus the 100watt is not cold running by any means. Radiant heat cannot be ventilated - and it will be 90deg at least anywhere within 6" of the light, meaning dry, scorched tops.