Nitrates can be removed with a water softener and fine mesh resin. I haven't tried it since I don't work on shallow wells. In my opinion (at least here in my area) the surface water here is nasty and isn't worth trying to clean up. Agricultural chemicals such as fertilizers, pest spray, and other things are just too abundant to clean. That and the PH is 5.5.
Whole house filters you see in the big box stores are a joke. Salt free softeners are also a joke unless they are the guys pushing softeners that use Potassium Chloride instead of salt. It's a marketing scheme, but costs about three times as much as using salt.
RO under the sink will remove a lot of stuff, but they have to be maintained bi-annually with normal usage.
You should be aware of the fact that bathing in water with chemicals (chlorine included) is worse for you than drinking it.
Get a local reliable company to do a water analysis for you. Someone that knows your area and it's problems. A lab is the best bet. Water analysis is expensive, but if you only test for what you probably have, it isn't too bad. That way you can get the right equipment instead of what some salesman wants to sell you. Salesman generally test for hardness, iron and not much else. Then they want to sell you a softener. They generally make all kinds of claims of what they will remove.
Basically do you homework. Then once you know what you need, come see me again. I sell this stuff and have excellent pricing.