I can select the 2d transducer (us2 at front or Low 200khz at back). I have LCG4000 GPS input to all 3 units via NMEA2000 and also my engine monitor via NMEA2000. I have all gauges except water pressure and fuel level. That requires additional adapters.

If you have Etek or Newer Merc, I believe you get all the gauges. Not sure though.
I got some help from Lowrance guys as the manual didn't cover the setup I have very well. Hats off to Todd Driscoll for his help.

I really like being able to select which transducer I wish to use. Saves me from moving stuff around.

I didn't install the livewell temp sender unit. Have to drill a hole in the livewell to get the sender inside livewell. My good drill is at the lake.Doh

I am getting it figured out. Good time to do this while I am baby sitting. ha