Several options with the 260 series.
The Airmar 260 series is the most sensitive 1 Kw transducer to date...about 44 times more sensitive than the 3 element B164...and 50 times better than the B60
Available as the B260,M260,Tm260 and SS264N pair.
And if only fishing under 500' the broadband 200 kHz side is available as a single flush mount..or a fairing mount.
On boats less than 30' many pocket mount the B260...but if the labor costs are too high the SS264 pair may be an option as they this option could be less in overall costs.
TheTm260 is good for many boats but will not work on stepped hulls ( The Tm258 is also an option here as it keeps the costs down as it is 4 element uint. )
Below is the 260.
The 50 kHz side is a 7 element ..and the 200 kHz side a single broadband. Being broadband it will give far greater target resolution and detail.