I have 3 Garmins on boat and remove a 106 Ultra sv and the black box to use it ice fishing.
For ice fishing I put it in a large locking Apache case and everything just fits, including a 20ah lithium battery. For some reason, I am tough on equipment while on ice and once I pack up, thats a lot of money safe in the case! I dont hole hop too crazy so no need for a shuttle.
To make it easy I bought all new power and the network cord so I dont have to strip them out of the boat every fall….now (for wires)I just have to remove the lvs34 transducer.
I like the 10″ size screen and if you use both, you will like it also. It does eat up more battery but I usually keep screen a little bit dimmer in shack and I make a solid 9 hours if not more with battery. Lasts even longer if I remember to sleep device (2 keystrokes) before going out to tipdown.
Your Transducer question is 2 fold. FFS is a standalone different transducer then the livescope. My regular transducer for side imaging, etc. stays on boat.
Battery? I mentioned the 20ah above which works for me…. I would suggest the 30ah if you can. I use 20ah since I already had it. On the boat, for years I used my regular cranking battery for garmins and Livescope. Now, I have a dedicated 100ah battery for the electronics as it got to be a lot of crap on one battery!