They mounted a rather small DDC unit under the PSU ...
I think phanteks has a slim DDC pump Res combo that can fit under the PSU cables. I'll link later.
I have an idea. If all this goes well, and the case is delivered, maybe I will hold a contest for the coolest custom water cooling rig. Backers and/or others can vote for the best rig. The highest or top 3 votes will get USD100 Amazon eGift card. I will post these rigs and their creators on my website and/or other reviewers sites.
Suggestions welcome.