best yield 2 x 600 watt

That sure looks like an HPS to me. The only difference seems to be an upgraded bulb which you could purchase for any 600w system. Maybe I'm missing something else. Do they have an option for an air cool-able hood? That was one investment that became inevitable later on for me and I overlooked it when I could have saved some cash on the package deal. Even if you aren't planning on running them air-cooled at first, it would be nice to have the option if it becomes necessary.

yep there is an option for air cooled i did ask about this :) , but the price for them are a bit expensive compare to basic HPS . as i said this guy said that they produce 80% more light than heat :S

sounds cool :D