Raymarine or Furuno
If you're serious about fishing, get a fish finder that does more than bottom reading and give you false readouts. I'm in the process of installing my brand new Furuno 620, I must admit, It took me awhile to bite the bullet, but I'm glad I did it.
Before installing the X-ducer I tested my F-finder in my 40 gl portable live well, I have about two dozen of extra large and medium shiners plus a large yellow perch (I kept the perch for this purpose and already released it back)
Here's a shot at the bait, you can clearly see the perch ( red) vs the bait:
Another shot with bait only, the darker colors are the extra large baits:
I can't wait to go out and try this bad girl :)