I added a Lowrance Hook7 to my 2013 22 SLX by mounting a Ram ball mount into bottom of right helm cupholder. I removed cupholder and then cut 1/2" pipe pvc spacers and ran stainless screws and nuts through bottom of cupholder into base of Ram mount. I cut holes in sidewall of cupholder big enough to pass the 2 cable connectors through. I then remounted the cupholder in helm and added a hose clamp on bottom side of helm to secure cupholder better. The Lowrance mount was used on top of Ram mount and I could then install and connect cables in a couple of minutes and remove for security just as quick. Now Ram offers a cupholder insert with an attached Ram ball mount (like the Weathertech commercials for cupholder cell phone holder) so you can do same thing I did much easier. I removed the setup recently as I traded in the boat. I used black duct tape to cover holes in cupholder and dash was back to stock looking. Hope this helps. My almost new 2017 Benny 22 SSRCXP has a dash mounted small Garman so I won't add my previous setup. I did add a Faria 2" depth gauge into actual dash on port side of helm to the right of 12v outlet. I feel more comfortable when I have 2 sources of depth readings as sometimes readings go unreliable for various reasons and I can compare numbers as afraid of shallow rocks. Not so good for prop!
Navigation only It has to have cell signal capability to have the built in gps and I am using the hummingbird fish smart app. The map cost 30 I believe. I like the hummingbird app due to the ability to set up the depth shading in red and adjust it for the fluctuation in water level