watch your wire sizes,use the largest you can to maximise efficiency..Id have the fans on a thermal switch or temp controller to eliminate any dc fan draw unless needed..you can use a small electronic module to control the fans,they are on eBay, they use a RTD or thermodevice you could mount on the motor(s) to monitor heat and control the fans (FWIW on eBay they are about $4.00each module-all the work is done for you item#203067392271)
I couldnt even build em that cheap myself.