What are your water conditions? How hard? Well or muni? Chlorinated? Taste? etc. What do you want the water to be like? Water treatment is an important decision and an expensive investment. When done right, you will have equipment that will last for many years. Done wrong, it will be more trouble than it is worth. Just read through athe last 2 days of posts and you will see that certain equipment is not well supported by the forum due to it being more trouble than the equipment is worth (most equipment sold by big box stores). Equipment manufactured by Fleck, Autotrol, Clack or the big companies, Kinetico, Culligan, Rayne, etc are typically very high grade equipment that has considerable support by the water treatment professionals on this site.
Have you had a water test done? If you are on municipal water, they are required to make available to you a full water report.