LED's are starting to become more recognized as a practical way to go. The newer lights coming out are 5 watt leds. I just bought a 400w a couple of days ago for $193 that has a decent spectrum. Take a look at this guys inventory.
http://stores.ebay.com/easyhydro/LED-Grow-Lights-/_i.html?_fsub=5274831018&_sid=1119652238&_trksid=p4634.c0.m322
The green lights are the older 3w models, the black ones are the newer 5 watt leds. I already have a 600w with 3 watt leds. Check the spectrum for the lights. If they don't list it, I would stay away. Red and blue leds are not proper answers, as different manufacturers use diff bulbs. Some of them come up short on the high side and only get to about 640 nm, which is probably not where the plants want it (660), and some of them don't start low enough. Red and blue usually only cover two spectrum's, missing spectrum's in the middle. Some are offering red, blue, orange and whites to cover more spectrum's. The next one I buy, I plan on going for the 5w all white led models. They seem to have a higher lumen output and are supposedly closer to the suns spectrum eliminating what is far outside what the plants uses. I also have blue/white 12" panel ordered that just now arrived as i type this;
http://www.yescomusa.com/45w_LED_Grow_Light_Indoor_Growing_225_Ultrathin_Blue.html. woohoo.... This will be used for starting seedlings as well as supplemental lighting as plants progress. I felt the 600w that i have got a little more stretch on the new plants than I wanted. So i ordered the blue/white panel. Is a 225 led at 45 watts. 5 watt bulbs on this one also. This will be an interesting addition. It is a panel, very light as it has no fans. Other items of interest i have looked and am considering are:
LED's in the t5 configuration. Interesting because it covers a larger area than the leds. When i started my grow, I had the 600w led as close to the plants as possible, and the fixture only being about 10"x14", could only cover 4 of the bag pots i use.
LED light strips. These come in reels about 15' long, can be cut up, have adhesive on them and are flexible. They come in the proper single spectrum for the color; 440 on the blues and 660 on the reds, some have white included. Was thinking I could put some of these on a dowel/post and shove these down in between plants to aid penetration.
FWIW, this is my first grow, I knew from the start I wanted the economics of LED's, and did not want to use the giant energy consuming type set up that many of the old time growers say are the only thing that gets volume. Didn't believe it then and am convinced now after all the research I have done (almost two weeks for hours at a time) that this is the way to go. I have an auto-seeds Kandy kush and Diesel Berry and a Delicious seeds La Musa (autoflowers) about a two weeks old, and two bagseed plants growing. started with a soil/sphagnum soil mix that ain't quite right on the autoflowers, learned something there! The bag seeds are in a soil/perlite mix and are doing very well. pics coming soon.