I want to replace my Lowrance transducer with an Airmar and I'm unsure of which one to go with...I've got a 2006 2320 SC, LCX-111C, and I primarily fish the Narragansett bay in water depths ranging from 10 - 70 ft... Been checking out the specs on the P66, B60, B164, B260, & the M260... Cost...