Which is best?Lowrance,Humminbird,Hawkeye etc? Looking for one that fits into a small gauge cutout.

Had a Lowrance on the last boat, Gaffrig on current one. Both look exactly the same to me, along with many other brands, and worked great as far as the head unit itself. The mounting location/method of the puck is what can make a $5 sounder work like a $1k unit, or a $1k sounder work like a $5.00.

I have a hummingbird. Like US1 said, the placement of the tranducer is 99.9% of the results.