well i mean more is always better, just as long as the ventilation is up to par.....how big is the grow area? Oh and on the aeroponics, if you want some real supremo bud that is def. the way to go, considering you say you have the extra time then that could be a really efficient way to getting the yield ya want, plus with some type of CO2 set up i heard it could also increase yield to 10-20% (don't know how credible that is)....so to sum everything up, of course more lumens....better bud! Also if you do want to do some type of aeroponics it would also be cheaper to build your own setup(if you don't mind doing the work :smokin....would save a whole lotta money and be just as efficient(half the price)
http://forum.greenmangardens.net/Vanilla/comments.php?DiscussionID=5&page=1#Item_0

Thats a link to a really detailed aeroponics set up that you could look it, but of course you don't have to go to the extreme as this set up, it's just a guideline....