I'm planning a gaming/workstation build, but intend on putting it in my desk's built-in rack. It has a 6U height, but I'm unsure how tall a case would need to be to comfortably fit a 3090. Cooling wouldn't necessarily be a concern, I intend on fully water-cooling; would just need to have enough space for routing the tubing and fitting the pump and reservoir. Any case suggestions?
As a side question, would it be necessary to consider MB and SSD water-cooling for this type of minimal airflow build?