First thing you will need to do is get a tds reading on your water as this will determine what will be the most
economical way to filter it.
If its up in the hundreds then a RO will be the best way if its in double figures then because your metered a DI only
might be better.
If your going to buy two poles then get an SLX18 or 22 and an SLX30 for all the rest, for work any higher than this I would recommend something like an Xtreme, but this will all depend on your budget and if needs be a CLX will more than do
your job.
Brushes are more of a personal thing and to be honest something your going to have to decide for yourself, I think the x line mono seems to popular on here at the moment but I have never used one so cant comment, the only brush I could never get on with was the Gardiner superlite and a lot seem to like it.