Sounds like to parts to what you are looking for.
Some thing to take out the chlorine and then a softener for the hardness that is in the water.
There are two schools of thought.
The older school with the softeners that have worked for years or the tried and true .
Then there is the new school that has more faith that it will .... and some say it does.
Both will be sized by a mix of max flow rate for the house and the capacity of each so that they are cleaning about every 7-8 days.
The most softeners use the max capacity but that is a little miss leading, it really should be at about 20k per cubic and 30k for the 1.5 cubic. That is really the best bang for the salt.