I have a PrimaLuna Dialogue Integrated paired with the Aria 936s’s. I too found myself in the same mindset of upgrading within a year of the new system but never really considered separates. I chose to upgraded the system by adding two subs, high-end replacing all cables, power cords, and the power conditioner. All replacements purchased in the used market (except the subs). Most impressive and surprising was the SR Powercell 12 UEF power conditioner. It was my second addition to the system after SR power cord for the integrated amp and I was taken aback with the improvement! In fact, I was underwhelmed at first, though, after bout 15 -20 hours of listening, I was dumbfounded. It was remarkable! Without getting into a bunch of adjectives, I basically now have a different system as far as soundstage and clarity compared my original system less the upgrades.
Now if I ever replace my Primaluna, I doubt I’ll consider replacing cables, power cords, and conditioner.
There is a school of thought that, assuming you will included high-end cabling and power cords, separates require purchases additional sets of cables and power cords. Everyone’s budget is different but certainly, something to at least consider.
I too must echo that speaker placement is paramount.
Cheers and good luck with your journey!
mb
Edit: I forgot to mention that I rolled some tubes as well.