I cheated a bit, and used a spare powersupply, plugged it into a motherboard, turned the pc on, then unplugged the motherboard, leaving the fans in. PSU is still running, as are the fans connected to it. made it nice and easy, as i can add/remove fans with ease.

the PSU adds a bit of extra heat, but i have it exausting out the case with anouther 12cm fan- its 69% efficient and the fans are only a few watts each.