Just thought about it before reading your answer lolYou could potentially shave down on the height some by routing your bulkhead connectors through where the reservoir is and not need the space directly above the motherboard.
Like that the space on the other side also shrinks and I still have to fit a reservoir and a pump in there, mabye I'll just go with an SFX PSU again and fit a high res/pump combo next PSU and rad (if something fits there) or I'll have to find another solution.
Because this would be a very expensive build which I cannot afford atm all this is on a very theoretical level anyways