I'm unsure what to build the rear retaining wall out of. I won't be able to go a rock or veneer look on it, because the size of it is just going to be an arm and leg. I'm thinking stucco with some veneer pilars, but wondering if there's a more natural look than stucco for a wall like this?
What I did is had my retaining walls shot with the same material they used for the pool shell. We then put a stone veneer on it
Ask the pool builders to price out all the pool equipment. See if any will allow you to get the equipment yourself.
I think 80k budget maybe a bit of low for the amount of work you are having done.
I really think by the time you get everything done your cost is going to be at 110k or more especially with such a nice design. So 87 k right now is really not that bad.