Greetings everyone. Just wanted to come back to post what I ended up getting for any future people searching for info and stumbling on this thread.
I ended up buying an Everstart DC27 Deep Cycle Marine battery with 750 cranking amps and 109 ah. I should note that I settled on this primarily due to weight considerations since the boat caps out at 395lbs. While there were mixed reviews (as with apparently all batteries I researched online) I decided on this one because A) It was walmart and I know I can easily swap it out within a year, B) I have an Everstart Battery Charger for the original battery I posted so figured I’d keep it all as compatible as possible, and C) I got it for $75 all in after finding a coupon.
I also ordered a set of angled oar lock sockets, a set or oar locks, and purchased a used set of lightweight aluminum oars from a desperate seller on offerup.
All in I spent around $115 and feel very confident with the end result. This morning my 12 year old and I ran the 40lb thrust motor at max speed for 3 hours while eploring the waterways and the second battery had more than enough juice left once we got home. (The original battery lasted just over an hour and I swapped before it ran all the way down)
Thanks again everyone, your input has been most appreciated!