Unfortunately, it’s not that simple. I can tell you which GPU cooler you need and roughly which components you’ll require, but in the end, you’ll have to measure everything yourself to see what actually fits into your Mini-ITX case.
Basically, you’ll need a radiator, a reservoir with a pump, the GPU cooler, tubing, coolant, and at least 6 fittings — two per component. But even if you tell me the name of your case, I can’t say for sure what will fit inside.
At the very least, here is the GPU cooler you would need:
Core Fullcover-Kupfer-Wasserkühler für Nvidia Geforce RTX 5090 Palit / Gainward Grafikkarten, mit aRGB Beleuchtung
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