What lamp should i use?

Hello everyone,
I have build kinda of hut and the sizes are :
length: 125 c"m
width : 90 c"m

which lamp should i buy?
I have 4 plants they already on 4 week they about 15-17 c"m, I grow "Early misty"
I grew them before outdoor and now i decdied to grow indoor.

I thgout about Philips Green power 600w

Or [URL="http://www.hydrogrow.co.il/products/42752"]Philips Green power 400w[/URL]

or [URL="http://www.hydrogrow.co.il/products/22430"]Sylvania GrowLux 600w
[URL="http://www.hydrogrow.co.il/products/22431"]Sylvania GrowLux 400w

I am not sure if i need 400w or 600w for my hut
what do you think guys?

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4 plants is 400w. So either will do. But 600w will give you more yield

Most of the time bigger is better... how is the heat going to be? how tall is it? I'm terrible with metric I think that works out to about 2 1/2 foot by 3 1/2 foot so a 400 watt will do but I'd choose a 600 with digital ballast that is adjustible..I grow in a 4foot square by 7 feet high and use a 1000 watt hps for my flower room. But I have A.C. and a cool thru tube..Remember it cost's twice as much to up-grade as it doe's to plan and do it right the first time. Don't look back and think "wish I'd gotten the digital ballast as you are scrambling to get rid of the horrible hum going through everything" or the fan or?? Now is the time to figure this stuff out in a worse case senario! Will I supliment CO2 will I need charcoal filters? Take your time before you buy look for the best deal's but buy what you like reasearch everything and all will go smoothly. Good luck my friend! jack