A well designed setup with good COB LED fixtures should cost less than half the power as a conventional light bulb based approach once power savings of chips vs bulbs and necessary cooling are added up.
Depending on how sexy you want your setup to be in that space, you could easily run less than 200W and get very good coverage, excellent spectrum and all the intensity you need.
In fact, one of
@robincnn's (Northern Grow Lights) Photon 180 fixtures would be perfect and could even handle a 3x3 space for veg or low intensity bloom.
3000K is about ideal for bloom, 4000K for all around use or 5000K for veg.