We use RO water for all of our beer, mainly because our water changes from up to seven different sources. Some of them would be great for brewing, some are terrible. So we take everything out and add back in what we need, this makes for a consistent product, and gives us some flexibility in our recipes.
As I recall, your water was on the hard side, but not overwhelmingly so. One nice thing is that it gets rid of nitrites as well as other undesirable minerals.
We bought ours for about 4000 usd, but that also included a water softener to pre-treat the water. Ours operates between 2.5 gpm and 4.5 gpm depending on the water temp.
There are no solved problems; there are only problems that are more or less solved.
All the best,Phibiche Diceus