Humminbird Fishin Buddy Fish Finders?

[RyanMac14]

So since I am not as brave as some and havent been out fishing lately, I have used more time than I would like to admit looking at equipment. Now since I have a small jon boat and am impaired in terms of putting things together correctly, I have shyed away from buying a fish finder. I have seen humminbird makes ones that simply clamp to your gunnel. Has anyone had any experience with these? If not any suggestions of a fish finder under 300 bucks that would be installed fairly simply? Thanks! On a side note, I have saltwater rods and reels that I would be interested in trading for freshwater. What would the best place on here or elsewhere be?