IMO, a whole house water softener is good if you or members of your family have skin issues or the source water is heavy with chlorine or calcium.
If you just want clean drinking water for you and your plants an RO system is more than enough.
At one of my rentals I bought a system from a company called Aquasana and installed a simple 2 stage filtration system under the sink. Came with a separate faucet dispener. No RO just pure filtration. One of the things I liked was that they asked me what area I was in so that they could tailor the filter to the areas water quality. IIRC, the system was around $120 and the filter set was $50. They had a program where they would send you filters every 6 months and would sell you the filters at a discount.
Enjoy clean and great-tasting water straight from your faucet! Aquasana offers drinking water filters, shower filters & whole house systems at an amazing price.
www.aquasana.com