Design help

I need some help with a grow box design, our budget is about £40, for that we can get about 8 34 watt wamr white fluoros, and leave about 10 for buildin materials, takin into consideration we wont need a fan cause fluoros dont produce heat. The money can be stretched and i would appreciate help, we are lookin for dimension of about 4 foot tall by 3 foot wide by 3 foot deep