building a pot room... Any suggestions?

i have a room and its dimensions are 78" tall and 80" long by 45" wide. so far i have covered the walls in reflective sheets (got them from lowes) also sealed the door and added a 6" duct fan with 250 cfm for fresh air. im planning on starting out with 6 plants but eventually would like 10 in time. im also looking at getting a carbon filter and also a 400 watt grow light. as of right now the total cost is only about $350. anything else i might need? ill be posting pics as i go along.