Lots of good stuff in this thread, maybe too much.
Forget about using a 12V 55# trolling motor on your 17 HPX-V. It's too weak for high current/wind situations, and your TM battery won't last 2 years because it gets drawn down >50% too much.
Go with the 24V 80# for the power and if you're going to use lead AGM batteries you should invest in a Stealth type charger to minimize the discharge of your TM batteries while you are on the water. Especially if you go with the smaller PC925's for size and weight. And you should because an HPX-V is very sensitive to weight in the bow. I ran PC1200's in the bow of my Super Skiff and they worked fine, although I think the Optima 34M Blue Tops that were in the bow of my Waterman 18 were better batteries for the same weight. But they are a little larger. Everybody I know that's running a Maverick puts their two TM batteries in the console, and their cranking battery in the bow. It's a PIA to wire, but gives the best balance for performance.
That self-deploy Ulterra will eventually screw you over if your TM voltage gets low or when that POS breaks. And that jog feature on the new ones is for fishing the bottom in open water. More of a bay boat thing
BTW since I switched to a 36V Lithium battery system in my new boat I don't use the Stealth charger I had in my Super Skiff any longer. Using the Stealth to recharge while on the water not only extends the battery life for that day on the water, but greatly extends the total life of your TM batteries by years.
It's still for sale.
https://www.microskiff.com/threads/stealth-1-charging-system-12-24-volt.48656/
I also have a couple PC1200's on a maintenance charger I'm not using I would sell for $150.