Trolling Motor Battery Help

[HawgWild]

I've got a Minn Kota 30lb trolling motor that I use to push an old v hull and a flat bottom boat around my lake.  I haven't used the battery in a few years and need a new one. The boats aren't on a trailer, I just push them out into the water. The battery I'm replacing an EverStart Maxx that weighs in at 62 lbs. I'd like to get something lighter to haul from boat to battery charger. I'm seeing some high dollar batteries (Optima Blue Top) that cost twice as much but weigh about half as much. Is it possible to get the same performance from the two batteries?

What's the most important number to look for - amp hour, reserve capacity?

Anything else I should look for?

TIA