The CX-120P is SPDT as per standard for a coaxial relay. I used to use an old Londex relay for the purpose of switching the FT-817 to separate linears and it worked quite well. I used a rotary switch and the power was also applied to the appropriate linear. I had the Londex “off” for 2m which was the main band. I have seen latching relays on eBay, but they have usually been multi-way. That’s not much use.