Up to about 1000watts in a semi-enclosed area in a room...just "cracking" the window is decent enough actually if the ambient climate is mild enough.

You sound as tho you are about to invest in your lighting. If so...go straight to HID's. Flouro is for young cuttings and growers on TIGHT space/power/security restrictions.
If you have a somewhat "free" room to use...400-600w HID right off the bat.