I talked to BRS and given my needs, they suggested the 5 stage would be good. No upselling, which I really appreciate (as always with BRS). I'll start there and see how it all goes. If anything, I'll just add on the chloramine monster and more.
Very true, though having some fresh RO/DI on hand makes me feel a bit better. I'll probably have a 55g reservoir of RO/DI filled at all times for my ATO + emergencies. Also considering doing most water changes myself, and having a maintenance service come every so often when I'm out of town for long periods of time or need some big maintenance.