I am in the market for a GPS/Chartplotter, and was hoping to get some insights. I am based in Texas, and will be primarily fly fishing in-shore. The previous owner has it wired for a Lowrance (including a transducer). I am not sure if the older transducer is compatible with newer Lowrance units or possibly other brands like Simrad. I would like to stay under $600, and possibly less. Thanks in advance!