16 GPUs in a 4U rackmount may look good, but have you considered about ventilation yet?
I think it could be hard, I'm willing to purchase if its price around 4800$ - 5000$ and each card temperature should be less than 73C.
Without scale, it'll be a LOT more than that, but with scale, I could get quite a good value.
Maybe even under $5K.
Ventilation is being heavily considered in our designs, and we'll actively select the GPUs that we install based on ventilation.
No promises regarding 73°C just yet, but I'm optimistic. We're really trying to put the airflow through the finished prototype. (which doesn't yet exist) Thinking either Noctua or Delta High-CFM, High static pressure fans. We've got a lot of fins to work around.