How big of a hps lighting system do I need?

Im only growing 3 plants right now in a little cabinet thing, the space is about 2.5 feet cubed.
2.5x2.5x2.5

So I was wondering if I would be okay with 150 or should I get a 250 hps or even 400?

If or when they get too big they will be moved to my closet where I have a space for them about 4 feet wide and about 3-4 feet tall.

A 250 would be smallest Id say.A 400 will cover a 3 foot by 3 foot area.Remeber your height as when going into flower a sativa will triple or quadruple in height while an indica will at least double maybe more so a 12 inch sative will be 36 inches tall then add pot height and room for the light ...The indica if going to flower at 12 inches will be 24 or more inches plus pot and light room...FilthyFletch