The biggest factor is, how big is your grow room? The two most important things to consider here are lumens per sq. foot, and light penetration beyond just the canopy of your plants, both of which are directly related to the size of your grow area. Also, going SOG from seed is risky. If you end up with males in your batch, it's gonna be a bitch to move all that shit around just to get to one or two plants. Just my $.02 though.