Lowrance, and Humingbird fishfinders are both good - Garmin is a good GPS. Do a Lowrance vs. Hummingbird search - you can reel your mind. Customer service should be a major concern. $400.00
isn't much in todays world. You might have to get a used one.
That shouldn't be hard. Alot of guys have to have the latest
stuff each, and every year. Good Luck!