It'll be fine, whichever orientation you want your monitors to be - it will NOT kill the monitors. In fact, Windows allow you to rotate the screen (90, 180, or 270 degrees): https://www.softwarert.com/rotate-screen-windows-10/
You would want to have a dual vertical mount for this setup, such as these:
The important thing is to check the monitor's VESA mounting holes against the dual vertcial mount's VESA bracket design if it will fit your monitor (specially the one oriented upside-down), as most brackets only rotate 90-degree max. on either direction when the monitor is mounted.