Tom
That boat should last a lifetime if you take care of it.
I just use Everstart Max 29 series from Wally World. I used to use Duralast batteries from AutoZone and I replaced them every 3 years for the TM. These batteries just started their 4 year of service in April and I'm still using them. I noticed a day at Cowan using the TM only they were tired at the end of the day but were still working. For most of my days of fishing They should be fine but if they show weakness...they're gone.
I upgraded the electronics a few years ago I went to a bigger starting battery (from a 24 to a 29 series) I didn't put a cranking battery in but I put a deep cycle battery since I have a consistently heavy amp draw with the (3) electronics, live well, bilge pump plus the starting going to that battery. It's only 2 years old and I just started to notice on days when I have the live well on all day it will pull the battery down low enough that it shuts the electronics off when I start the big motor. This battery is only 2 years old. It's still a wait and see how this battery lasts the remainder of the year.
Either way I will replace them this fall/winter if they make it that long.
I'm thinking of putting a separate battery for the electronics but I have no idea where to put it or how I'll keep it charged.
I had a set of Optima's a friend gave me after he used them one year, he didn't care for them. I used them the next year and wasn't impressed. He's not the kind of guy who takes great care of his stuff so I don't know if that had anything to do with the mediocre performance or if it was just the nature of the beast. I do know I'll never buy them.
I have a 15amp BPS 3 bank onboard charger. It charges everything overnight just fine no matter what I do the previous day.
I hope this helps.

PS I tried to pull start my 40HP Merc...it dang near killed me and I never did get the motor started.
Just sayin.