I upgraded some of my electronics last year. The old GPS died and the VHF was not working so I replaced both of them.
I ended up with this GPS unit:
https://buy.garmin.com/en-US/US/p/529894This was the old early 90's or late 80's GPS unit.
This is a pic of the new unit:
I ordered mine without the transducer. I wanted a dedicated GPS. The 9" screen is really nice and the detailing of the charts is very good IMO.
I also installed a new VHF with DSC. The DSC is a good safety feature. If you are in trouble you push the red button and it will transmit your location.
I would recommend both units as I am very happy with both of them. I also bought and installed a new VHF antenna. Prior to the new antenna I could pick up 3 of the 10 weather channels in my area. Now I get 7 of 10. Last season out on Lake Erie I was able to listen in to radio conversations 40 miles away quite clearly. Get a good VHF and get a good antenna so the radio can function at its best level.
I was contemplating replacing the depth sounder. The one that came with the boat is ancient tech but it still works. All I want out of a depth sounder is how much water is under the hull. So, as long as it keeps working I will continue to use it.
Here is a pic:
It has an in hull transducer and comparing readings to the chartplotter depth readings it is accurate.