Storage currently is x2 990Pro NVMe SSD’s. The bridges for paired 3090 gpu’s help a lot, so instead of both boards traveling back down the PCIe lanes only one needs to, enhancing speed. Cards on these 3 slot bridges will be close to each other but not touching. I will have fans under the cards aiming up (hot air rises) to get rid of heat from gpu processors as fast as possible. I see a lot of fans. But i have built similar and it should be pretty damn quiet. 24GB of vram per 3090 x 6 or more is healthy. Avoiding overly aggressive quantization, opting for higher-bit precision to preserve model fidelity.