Most growers swear by 600 HPS for budding, but I use 1-1000 and 1-400 in the bud room (1000 w on a light rail) for 6 x 14 feet of grow capable area. The light rail moves the 1000 w three feet each direction.

***600w and 1000w are both designed for 6 sq ft (double-check @ hydrofarm.com). The difference is, the light can be placed closer to the plants with 600w.