I basically in the same boat as you

Looking for the best deal for a FF close to 350$

I was going to go elite 5 non dsi only because what I have read is dsi gets very sensitive in salt and with swells. Also limited to 200ft

I'm still looking and reading trying to figure this stuff out so I can make the best descision possible.

Have you looked at any of the humminbird or garmin units? I know even less about them but from what I've researched it looks like they have some comparable units in this price range. I just have been focusing on lowrance b because it seems to be the crowd favorite and what people have the most knowledge of. I used a humminbird 386ci for a bit andi liked it but I'm trying to get something witha more detailed structure image in deep water and not sacrifice having a gps

I have the humminbird 398ci and love it

Is that the one with side imaging? How does that work out in the ocean