600w in 1metre high

ive currently got a 125 envirote with 6 feminised seeds in an 1mre long, 1metre high and 50cm deep, the plants are 2weeks into veg and about 15-20cm high.im about to put them into bloom and so going out tomorrow to buy the light, need some advice on wether a 600w hps on top of a glass window, would be to hot. The room is beening vented via a 125mm ruch fan connect, and a and ocilating fan in a fix possition drawing air in. The plants have 50cm of growth room so i got to keep them short, anyone used a similar size room, if so what light and yeild did you get?:confused:

2 weeks and theyre 20cm tall? How far away is the light?
Edit: get the 400w instead, Im growing 4 plants under a 600w HPS in a closet - 2.5ft wide, 2.5ft deep and 5 feet high, and Im only just able to control the temps. And dont put a sheet of glass under the light to try and make it stronger - it doesnt. Glass absorbs light.

My first grow was 3 ft. X 5 ft. X 5 feet high. I can still feel the pain from leaning in contorted positions tying to water and maintain. I got 5 plants that grew under crappy lighting - two went hermie on me. After that I got off my butt and enlarged the space to 9 ft. X 5 ft. X 10 ft. high on the second grow. Now on my third grow I've realized you can pack them in with enough light. Grow four - I'm expanding to 9 ft. X 7 ft. I'm sure in time you'll find a way to get more space, but for now GOOD FOR YOU!

the glass isnt to make the light stronger, its to keep the heat away, theres going to be a hole in the glass to allow the air to flow,still think its to high