Also I'm concerned that anything bigger than 120 will have to go on bottom. Which doesn't give the fan much breathing room to cool the rest of the card.
My case gives me a few options. Looks wise though a 120 (aio) will be cleanest look, will a 120mm radiator cut it?. (Not overclocked), but stock cooler gets into 80's easy.
Its the inwin 101, the side mount already has a cpu aio watercooler. Which takes up space above the third case fan mount along the bottom. With the height of the radiator it can't take a fan. (or vice versa). The other option is a 120 aio on the back case fan mount and three fans along the bottom. That would look nicer, but I doubt a 120mm radiator would cool a 1080.