I have a SiTex GPS the old kind that only has read out of location, speed and direction. Its that old lcd screen that has an old data output on the back that is coaxial of sorts, pre-usb. It just keeps going. So I suggest SiTex, I don't know of their new equipment but they have intgrated systems that look promising but can't attest to anything new because the old one is still a work horse. I would guess it's over 10 years old from the previous boat owner.
Good luck and let us know what you decide and how it serves.