I run Helix 9" units at console and bow. These are Gen 2 versions with side/down/2D traditional sonar and GPS with mapping. I can tell you that anything less than a 9" version is difficult to see the details, particularly when standing at the bow. You should look at the Helix Mega units with chirp. Images I have seen on the internet forums are quite incredible. I bought my units from BBG Marine - https://bbgmarine.com/
If you have any questions call them, his name is Brian, and he is extremely helpful.