Navman Displays -- Old Boat

[flagorio]

My navman displays are no longer displaying depth, wind, speed. I need to replace speed and depth in the next two months. The boat is a 1963 Rawson Ketch heavy cruiser currently in Ohio headed south come spring. I am looking for value as I hate it when cheap stuff breaks. I have a Garmin GPS, Raymarine Radar, Simrad Autopilot, Sail-O-Mat wind vane, computer with BU-353 GPS puck, Seaclear, OpenCPN, etrex legend, Horizon VHS, Nauticast 2675 AIS receiver, Cradlepoint wireless access point, cellular usb modem with masttop antenna. I am pretty technical.
My questions are: how to proceed (network vs standalone), best source for instruments and transducers, when to buy (in next two months).
Thanks for sharing your experience.
Frank
S/V Escapade
"Fairly warned ye be, says I"