PC7+ II - You can fit 120 rad at the back. Its small, neat and weighs less than a mouse.
but there's no reason for you not to be modding young man! If worst comes to worst strip the panel and send it to WCUK/AquaPCs and get them to cut a 240 mount in the top.
If theres still any 160mm (2x80mm) rads about you could consider a HTPC case. But i wouldn't tbh.