Finally bought a house and got away from renting. Really need a softener and trying to figure this all out. Here are the details and what I have come up with.

1.5 bath standard shower and tub.
no dishwasher but will get one eventually
1300 sqf home two adults
currently have old galvanized plumbing with buildup in pipes that will be updated to 1" pex to a home run manifold with 1/2" to each fixture and of course separate line for outside spigots.

On well water with in ground pump and pressure tank in basement
water tested as follows

No copper
Iron didn't show up on test I'm thinking if any there's 0.1 to 0.3
No Nitrate/Nitrite
PH 7.5
No Chlorine
Hardness 21 gpg

It's hard to figure flow rate at the moment because the lines are so bad but, I got about 1 gpm out of tub.

I'm thinking of the Fleck 5600SXT electronic meter on demand 40K Grain and set to regen every 1300 gallons. Would really appreciate opinions and other suggestions and let me know I missed any needed info.

Thank You