As for the paint, The paint you choose looks sorta like interlux style paint which is usually used on bottom painting on boats. I have it on my 30 foot robalo express fiberglass fishing boat.
I saw your paint scheme and im not sure if this will work for u but I used parker coating paint. Its flat paint though. It came out amazing though and I love the finish and the toughness.
There is also rustoleum that people use with self etching primer. I used this method while painting an outboard cover and painting another aluminum jon boat and I loved the finish actually. The outboard cover was great! you could even see it shine.
Thats the route I would go.
If you are wanting bottom paint and want it slick down in the south we run a brand called frog spit. You can get it from Predator airboats. All the airboat guys run this its about 65 dollars a gallon and it makes the bottom of the boat super slick! Im adding it to my 1648 now.
Im doing research trying to find a thru hull fitting for your live well. I havent found anything as of yet but the coupling sounds like a good bet to do.