I've been running a mix of drives in my NAS setup and noise is definitely something to consider when it's in your workspace. The WD Red Plus drives are still among the quietest options, even at higher capacities. If you want to stick with the same quiet experience, go with the 14TB Red Plus (they're like 20-21 dB).
For what it's worth, I've found the Toshiba N300 and MG series to be a decent middle ground on noise vs capacity. Definitely quieter than the Exos which sound like jet engines when seeking lol. Whatever you choose, check the specific model's acoustics in the spec sheet rather than just the product line.