Couple of questions.
1. What are you mounting it on? Slide track, Ram ball mounted straight to the kayak? My suggestion would be a 4" gear track from Yak attack. If you don't like it where you put it, at least you can move it and put something else on the gear track.
2. Do you want the cords and battery on the inside or outside of the hull.
3. If inside, are you comfortable drilling it provided you had good directions and items needed to make it water tight.
4. How would you prefer to mount the transducer. My suggestion, would be to use the mad frog liberator arm on a 4 inch gear track.
Here are two of my videos on how I did it.
1. - My very first video - Its rough...so sorry about that. But if you'll skip ahead to 1:49 you can see how I did it. Directly applies to how you could mount yours. https://youtu.be/7LgmAMMVyYg
2. Most recent video - You'll see a big difference...lol. This shows how to use the Hobie thru hull mounting kit, which is what you'll need if you decide to drill it. https://www.youtube.com/watch?v=BZwKHL4sNX4