At some point i may change the bottom rad to a 360 too, top one ill be a EK 360 PE. bottom is EK 280 CE. Not even sure if the 140mm fans will fit at the side yet.
thx
My O11D Mini accepts 140 mm fans in the side.
However I went with the 120 mm size because I wanted to run those two intake fans and the back exhaust fan on the same fan header and the case will not accommodate a 140mm fan in the back. My mini-ITX motherboard only has three fan headers (the other two headers are for the CPU radiator fans and GPU radiator fans respectively).
If I recall correctly, 280 mm radiators and 360 mm radiators have comparable cooling capability. There is more selection and variety available in the 360 mm radiator size though. Same with the 120 mm fan size.
My top CPU radiator is 20.5 mm thick, the XSPC TX360 Ultrathin. The bottom GPU radiator is 30 mm thick, an Alphacool NexXxos ST30. The case has enough clearance for thicker radiators in both locations but I (correctly) estimated that these two radiators would be quite sufficient for cooling their respective components.
My O11D Mini case was a dream to build in. My loop has plenty of cooling capacity and the fans run quietly even when the system is maxed out, whether it's a Handbrake encode or a gaming session. Mission accomplished.
Hope you have fun building yours!