Good advice above and great choice on the boat. I ordered the same. My 22LSAPG is being delivered in 2 weeks (150 Yamaha). I am a serious fisherman, and working with my dealer they ordered for me accessories/electronics to meet my needs and will be installing after delivery. I also have a 18 ft Deep-V, but my wife wanted some luxury in another boat; and eventually I may sell the deep-v if I am content with the outfitted pontoon. This is a boat I will be keeping for 10-15 years and not shorting myself on the electronics.
Chat with your dealer's service team. As always, it really depends on how much you want to spend. Check out the youtube "Ultimate Fishing Experience 2019 Episode 11 - Pontoon Fishing Boats" from Wired2Fish. The default Garmin Striker 4 in the dashboard is not going to suffice if you are thinking about more serious fishing (I added it my build--but just for general depth info). Humminbird/Minnkota, Garmin, Lowrance, Motorguide are all good options. Depends on preference. So, I am adding the following:
--MinnKota Ulterra 60' (72' was determined not needed--and my dealer's service team are competitive anglers). They felt it would pull enough for my Northern Wisconsin/UP Michigan waters. Now if on Lake Erie or Green Bay's big rough water, I would consider the 72'. Spot lock and iPilot is a must and the Ulterra's automatic deploy will be nice on a pontoon. Batteries: 3 for TM and 1 Crank/Starter battery will be stored in the privacy station (no privacy). Get the detachable mount, so you can remove the trolling motor.
--Humminbird Solix 12 --touchscreen, Side-imaging, 360 imaging etc. Mounted on the helm.
--HELIX 10 upfront in Bow (that I will pop in and out from other boat). The Bennington sold me on the roomy bow. I will be able to stand, fish and use the trolling motor remote/lanyard--I am not a big foot pedal guy anymore. I do a lot of trolling out the stern and it is roomy back there also.
--Talon 12 --on stern to be used as anchoring, beach, dock etc.
--MinnKota 5 ethernet Hub (the MK and HB devices will all 'talk' to each other); and the hub makes it easily expanded to add other devices. (i.e. a Talon up on the bow; a different depth-finder)
--ProTour 360 Elite Quad 4 Bank Charger
It's a lot of add-ons, not cheap. But if you really love to fish, these are some great tools.
I will send pictures of my Bennington once delivered on outfitted.