Sorry to be the one to say it but i personally think u`ll be lucky to grow a few seedlings with the light set up u have in there!!!
Think u really need to go back to the drawing board and do a little research!!
As regards yield??? with 4 - 20 watt bulbs giving off a pitiful lumen i`d say u`d be lucky if one plant would even make it to the flower stage by this time next year!!!
if u got a joints worth u`d have done a top job!!
Good Luck
Digi