Um well i believe with HPS i keep mine above my plants a good 2-1/2 or so ft [making sure you have good ventilation so the tops dont get hot]. With Floros they can be like a foot or so becuz they dont get as hot, again ventilation is important.

As for soils theres a bunch out there, i use [becuz of low funds] a dirt cheap mixed with some better potting mix type soil, but im not the best on soil so i dont wana steer you wrong.

Sex can be determined, but only after you've started your flower cycle, males have sacs of pollen, females have white hairs [pistols].

Pot size depends on how big you wana grow, i always say a gallon for every foot of the plant at least but the more room, the happier the plant. I usually have plants im growing to about one and half feet to two in a 2gal pot

GOOD LUCK, keep us updated!