you will have to dig a bit to figure out which way is the best to go.
You can buy the boat version, and then "ice it out" with a bag, battery charger, and transducer
or buy the ice version and get an extra gimbal mount, power cord,and transducer for the boat.
I'd buy the boat version ( I did) and then get a Genz box/battery/charger off Amazon or such, and get the new 1521 ice transducer.
MAKE SURE YOU BUY A GEN2 unit! Gen1 will not chirp or accept the update for ice mode, which allows the CHIRP to be used ice fishing and
it adds other features as well.
It took me all summer to get used to the new tech in my Helix7 but it is a great machine once you're used to it.
Mine is 2D/DI/CHIRP/GPS/Gen2.
If you get the SI version, it will DI as well and 2D.
SI/DI will only be beneficial while moving, not staitionary.
Then there is the model with the "N" on the end, which is for "networking" if you want to run a I-Pilot trolling motor, or have multiple sonar units on your boat.