If you want a robust keyboard, go mechanical. Quiet is relative -- there's a number of different switches to choose from. Cherry MX Red or MX Clear are both popular picks for office environments. I love my Ergodox -- I have one with Cherry MX Green switches (very loud/clicky) and one with Zealios (very quiet, but there's still a tactile bump at the activation point of the key so you don't have to bottom out the key).

https://www.reddit.com/r/mechanicalkeyboards is really the right place to ask, IMO.