The Marcum Showdown troller would be about the best option in my opinion. Small, light, AA batteries, inexpensive, and it works great.
This is what I use. The bracket that comes with the performance pack attaches to the thwart with two zipties very nicely. I remove the unit/ducer from the bracket and store in a small waterproof box overnight. Transducer shoots right through the bottom of my kevlar canoe as long as I put a little water in the bottom. Have never ran out of 1 set of batteries after hard fishing for a week, but I always bring an extra set just in case.
I have caught exponentially more fish in the BWCA since I started bringing this. Perfect for finding dropoffs/humps that walleyes love to hang out on. It even picks up your jig and will show fish coming up to get it.