IMO most all of what you are contemplating is the worst choice you could make. First, the GO is the worst choice for FMT. Ask yourself this... what functional advantage does any GO unit have over any other compatible machine? The answer is none... Only disadvantages and that is the reason it is inexpensive. It looks sleek and that is about it. I would never have a GO. It's a total hassle to use on any small rig compared to all of the others. Second, flush mounting on any small boat is the worst choice for a host of reasons and particularly if you have to have a GO. As for Navionics, what will you do with that? There is nothing on there inshore that will be unique or better than the other. Not even close. Its even dangerous to use in many areas. Perhaps you can get some use for it out past the reef lines if you want 1' contours in 50' but that's about all. Pick up a used one for $50. They are all over the place. Most FMT users never use their Navionics again. You could probably find one for free.