I wouldn't buy a pool because I like the salesman.
You mention rocks, so your location is north of Gulf Coast?
Location does matter. Where I live 12" centers for the steel is unacceptable. However, there are pool builders that will cut corners in that area.
A couple of my amateur observations.
I think you need more lights $$$
Heat pumps are for more northern climates so to extend the swim season. They do not have enough heating ability to bring a spa up to temp quickly.
I'm not a fan of pump operated pool cleaners but that is me.
The fist quote mentions 350 sq/ft decking. No mention of decking in the second. My experience is that is usually not enough and you'll want more $$$