Contacted Jim Maier at BOE Marine to see what I could replace the Navman with, and his reply was the same as some of the folks in the Marine Electronics section.
Jim recommended a Lowrence LMF-200 as I wanted the same form factor as my old Navman, and I wanted something simple.
All I wanted was fuel burn (in gph), a low fuel alarm, fuel burned, and fuel remaining.
Now, for the record, I am not a fan of Lowrence products, but this item seemed to do the things I wanted without breaking the bank.
I was willing to take a chance.