Hi Mirabile,
My current setup is as you describe it, I have just more RAM (I have installed the extra RAM modules myself) and my audio interface is RME.
In the past my old setup (several Macs, PC, switch, screens, cables, etc...) was +- stable. However I have spent remarkable amount of time maintaining my setup. Since having ONE very powerful machine, my mind is completely decluttered from any technical issues and I can just concentrate on writing/composing/orchestrating music. Although my composing template is huge, it loads in a very short time. The disadvantage is that I have no more time to make a coffee/tea while the template loads so fast 😉. This machine is so powerful, that I do not have to look anymore what shall I load/disable, etc...I have never seen the CPU cores to spike, or rise, whatever. Even with a very busy composition (and running the picture as well) the machine is very stable. It’s fans are running at very low speed - I cannot hear them in fact.
So, what shall I say? I highly recommend your machine choice.
I cannot comment on the audio interface as I do not have either of them.
One more thing, I do not use any plugins (just a limiter) in my DAW as I "mix" the stems in another DAW (on the same machine of course). But again, even there I do not need many plugins either. I cannot comment what would happen if I would load many effects...
Hope this helps.
Stefan.