[McGillicuddy]

Hey et phone home, heh,heh. I'm im the middle of the same debate. I think you'll be fine with that transducer. obviously its designed to mount on the transom but it will work insid the hull. I've heard from some that the transducer loses some sensitivity at depths but for inshore work it is common practice.
I, personally, would shy away from the epoxy. My fiberglass supplier has suggested silicone for that type of application. You will be able to mount it at a better angle, and remove it when the time comes or if you want to mount it on the transom. Its the closest you're going to get to something like ultrasound gel in an adhesive and it should hold up ok in the bilge. Just make sure you wipe down the mounting position with acetone or carb cleaner before mounting, and avoid air bubbles. Good luck.