I have a 20' Glastron 205 SF. I am looking for a good GPS/sonar combo with a shoot through hull transducer. I want about a 5" screen, nothing bigger, in color, in the $600 to $1000 range. I was thinking either Garmin or Lowrance. I know a lot of you have these, and I would like to hear what you have and why you chose it. Reading the specs on both systems, they all seem pretty similar.