They have 500's, I suggest for 2 600Watts.. and since you know they spread better.. I will give you a fiiferent reason.. you may decide later to do a SOG,etc... where you need on light for VEG and one FLower, this way you would have the light allready.. Also.. if a bulb blows in one... you have the other until you get a replacement... or if one ballast fails,etc,etc..