I am looking at buying a fish finder for my boat. The finder will be right in front of my driver side windshield. I am just looking at a cheaper model, as I don't do alot of fishing, but I was curious, what needs to be installed on these? I am sure I will have to get power to the battery, but the transducer, is there a certain one that is better than the other? I am looking at the humminbird 525, I believe it has a transom mount, is there any drilling required for this? Just curious, thanks.