What phone to choose for office standard CDMA-450?

Question

Telephony

Hello!
At the moment, our office uses a Skylink base, to which Panasonic KX-TGA550RU devices are connected. The main task is the ability to switch calls to neighboring phones, but the quality of the devices themselves leaves much to be desired. Very quiet speaker and often glitches with interruptions in communication.
Interested in the availability of similar devices that meet the minimum requirements. Support for a base with the CDMA-450 standard and the ability to redirect a call to neighboring handsets.
Thank you!