honestly, this is just a personal prefrence, if i were u i would get 2 600ws instead of 1 1000w. one central source of lighting has to be held higher to cover the same area as two medium lights would. if u got 2 600w hps u could drop the lights closer to the plants, that would make them grow faster and u would need less side lighting than u would with just 1 1000w. 600 watt lights closer to plants will provide more lumens than 1000 watt lights further away from plants.... and dont buy the 1000w switchable ballast either. if i were u i would buy either 2 400wmh, 2 600wmh, or 1 400wmh & 1 600wmh, (what ever your budget allows but it shouldnt be more than what u were planning to spend any way). mh hid lighting makes the plants grow sturdier so a lot of growers use them for VEGGING not flowering. hps makes the plants grow taller and allows better bud developement. they also produce more lumens per watts than mh, thats y if u had to choose between the two u should go with the hps, but the stalks are thinner so the idea is to use the mh for vegging to get a sturdy/ thicker bottom and a hps for good bud developement. but u can actually use both at the same time and get better results than using either independently. just make sure the foot print of the mh over laps a little with the foot print s of the hps. every where the mh and hps the plants will be bigger and better than the one's receiving only one spectrum of lighting. just use more hps than mh . and like i said before u should try to find those lights used and dont buy digital ballast. the mass majority of the bulbs on the market are designed for magnetic ballast. if u use a normal bulb in a digital ballast it would work, but there have been A LOT of reports that digital ballast burn out bulbs 3x's quicker than magnetic ones. currently there is only one bulb maker on the market ( whom's name i cant recall) that has solved the problem but i think they are expensive if i remember correct and its not really worth it.... one more thing u need to think about is electric usage. using alot of electricty for your set up can over load you circuits i think u r only suppose to use 1400w continuously ( for more than 3 hours at a time) some houses are wired to handle more but i would go with the lesser if i were u. if u need more juice use a different circuit. find your breaker switches they should have labels telling u were each circuit leads to and just plug up the extra where ever the cicuit leads to