Personally I think LED lights for growing at this point are all gimmick.

The ones that do put off decent lumens in the PAR spectrum are all using the latest generation of LED's, and they are very expensive.

For example, the illuminator pro is $1200 and consumes 350w. They claim this is the equivalent output of a 1000w HID

Same deal with advanced nutrients "stealth" series LED light. 350w, $1600, claimed to be the equivalent of a 1000w HPS.

Neither company has released an independently tested output chart, so personally I don't believe their claims.

In your closet you should definitely be able to get away with a 400w and maybee a 600w HPS.