CFL is compact fluorescent lighting. It's basically a low energy using spiraly bulb. You can grow with them and you're correct that you would probably want at least one each of the 2700k and 6500k bulbs. These numbers are referring to the colors the bulb is putting out. One is going to be a warmer color and will be your reds and the other will be the colder colors and light in the blue spectrum.
If I remember correctly, plants only need the red and blue spectrums. I read somewhere that if you only have one, use the 6500k.
So you can definitely use these as grow lights and usually come out cheaper, because they aren't labeled as special "grow" bulbs. You can buy the special grow bulbs and they may cover both of these spectrums in on bulb. Or maybe they're a long bulb so you can cover a greater area. There are charts as to how high any light bulb needs to be above the plant and how large a radius it's recommended to cover.
There is another type of bulb I've never used called 'metal halide'. They are supposed to be good bulbs and are used in large grow houses, but they're expensive and dangerous. They get searingly hot. Not only can this burn your plants, but you as well.
An alternative to the CFL bulbs are the LED bulbs they're starting to come out with. The light looks purple, because it's alternating straight blue and straight red lights. It gives it a pinkish purple haze. I think I read somewhere, though, that while these are great for plants, they aren't great for human eyes.
This will give you something to look into and hopefully point you in the right direction to learn more about your lighting sources. I'd personally stick with the CFL bulbs, because they are low energy and give off very little heat. Just look at the charts on the internet to see how many you need for a given number of plants. (IE: You'll need x amount of bulbs at 18" to cover so many square inches of plants, like a 17"x22" nursery tray.
