hey themasta09 thats cool man youve got a nice set. my space is also the same as yours, 4wide2deep6high. im growing in a caravan. which has its pros and cons.

i have 5 sensistar in a 20L NFT system which is basical one big pot with a continous supply of aired nutes flowing over the roots... 600 duel spectrum hps. i have 2x 25watt 5inch clip on oscilating fans.
2x280cubic meter and hour fans one in one out. and a dehumidifier.

this picture is about 2weeks now old so the plants are 3weeks old in this picture..

you can see that the plants look a little bit unhappy. its taken till today to sort them and i think im in the right direction now....

iv added a little co2 but the yeast method seems too much hassel....so im soon to invest, in the bits and pieces to make my own co2 system as the shop baught ones are so over priced...

iv had my problems with nute defficiencies and aphids too...

hows your plants now then as they must be all coloured up and smelling sweet as....

ps what made you go for the lower wattage option?