No, I agree, and I went through a lot of research
and reasoning before I decided that "old school" was the way to go.
I had two T-105s as the house batteries when I bought the boat. They lasted a remarkable 18 years (from the boat's launch in '88 to when I bought it in '06...a remarkable run.
I'm moving the house batteries to mid-boat, and I have yet to decide between L-16s or T-145s, but I want it to add up to 1,000 Ah so I can make ice at anchor
for five cloudy and windless days. I'm fairly strong on big capacity/small draws. Having a full keeler helps that decision. It's got to work (ideally!) for five years, so dollars aren't as big a consideration as getting a strong battery that can take a lot of cycles but rarely face a 50% discharge...that's one of the reasons I want a big house bank, to stay above 75%.
A Group 31 makes sense for a start. Not sure how I'll do the windlass battery yet, but your suggestion is good as that area's going to be tossed around more than amidships.