I have two Lowrance that I am very pleased with: Elite 7x-hdi (no gps/charting, $499) and Elite 4chirp (has gps/charting, $329).
7 screen allows side-by-side display of 2 things; 4 screen allows one tall display or over-under display of two things (I often put 200khz sonar top (better for fish) and hdi image bottom (better for structure/logs/weeds).
gps/charting for me basically gets me MPH over ground data which helps with trolling, I don't actually use the charting much but I wanted it on the 4chirp unit for when I take my kayak into the ocean plus the 4 uses about half the power that the 7 uses...
both these units are great for kokanee and tidewater salmon fishing...based on my experience with the elite-7 and elite-4, I think you would be very happy with the Elite-5chirp with gps/charting ($499) if that fit your budget..