GW,
I am fan of Garmin products.
The Garmin 546s is a nice unit with sounder.
http://www.boemarine.com/marine-navi...tm-transducer/
The 740s is super but a bit over your budget.The 740s has a sounder with a touch screen and a very fast processor. However the 740s would give you the ability to add radar in the future.
http://www.boemarine.com/marine-navi...ter-w-sounder/
Can't help with other companies choices. I'm sure there are many otheres and some that might be better priced.