There is my suggestion, since your company apparently doesn’t have the expertise inhouse.
All these items must be spec’d and maintained properly to meet your requirements.
Personal suggestioncoarse filtration, water softening, activated carbon sorption, nano filtration, multi pass RO followed by mixed bed DI polishing. However, without any contaminants whether it be deionized or neutralized, This is distilled water. Now look. Use most of the excess heat or steam as it comes out of the turbines to distill water for water that is even purer than DeI water. Certainly, contact a reputable supplier of bespoke water treatment systems with some indication of the feed water analysis and the product water specification, and the quantities required.