I used a cell phone charger as an adapter to the 5 fans inside my pc box. You can use any kind of power adapter from most appliances...
To be honest, 5 fans in my 1.5ft cubic growbox is still not enough! Looking at yours, I can tell you need to get an oscillating fan (dosent have to be, but its good for the fan to hit the whole grow area, rather than just one spot). Just get some small fan at walmart for like 15 bucks. The plants will do much better with airflow... Afterall you are trying to recreate nature as best as possible!
