Side and down imaging only work while moving at 3-6mph, that is not going to be very helpful on the ice. I think Humminbird has the best side/down imaging there, although the competitors are excellent as well.

I think Garmin has some of the best 2D sonar. Set scroll speed to fast and the gain to auto high, a 1/32 oz jig will show up just fine. If you don't need the maps a Striker 4/5 is hard to beat for the money, although at this point I imagine something like an older Echomap 7SV has to be pretty affordable.