I amm flowering a NYCD and a Fantasma(AK-47 x) under a 1000watt agrosun gold metal halide...the buds are kicking ass...

Although an HPS has a better spectrum for flowering, It is not imperitive. You will be fine starting out with a 150w agrosun.

Keep in mind that the less heat and the smaller the grow is better for new growers, because it eliminates some of the bigger problems during 1st grow. Goodluck