Almost all brands have a 5-7" screen fish finder with GPS. They're all good, but picking the one that's "good enough" for you depends on your needs - and the size of the bank you're trying not to break. I like Humminbird, but in honesty Lowrance, Garmin, and RayMarine are just as good. Fans of each would say better.
Just one source (with reviews)
HERE
