Smallest case for atx board?

what is the smallest case/chassis for an atx? because i wanna try to fit a maximus vI fromular motherboard in it cuz it has liquid cooling for it...

and what would be the best pump if i want to cool cpu, gpu, motherboard? in a 2 fan size rad?

 

or should i really scrap the maximus 6 formular and go with the gene?, but still what pump?