water filtration systems

Hi, we are currently having our kitchen renovated and thought this the ideal time to install a water filtration system.

Does anyone know of a company or individual who could best advise us?  Ideally I would like to have whole house filtration system but obviously this comes down to cost.  At the very least I want filtered water for drinking and cooking to avoid adding more plastic bottles into the environment.

Have been trying to research different systems but am finding it all very confusing.  Reverse Osmosis systems appear to waste a lot of water and can be costly to run, is that correct?

Thanks in anticipation, some guidance would be very helpful.