Take a deep breath. 2000w of HPS should be plenty for flowering, but I would use a MH for vegging, if it were up to me. LED will supplement the spectrum, but they really like the blue light during veg growth. Regarding the nutrients... go easy on them. You didn't mention the type of soil or if you have any nutrients in it already. You have enough hardware to have a decent grow, but use some patience and restraint before starting to pour this stuff on them and possibly overfeeding or getting nutrient lockout. It is VERY easy to do and difficult to recover from. There are a million other tips that might help, but take small steps and you will do fine.