Thanks a lot BurrMan for sharing your point of view.

You're right : we are in the same boat!

In the meantime I'm doing a web search here and there trying to figure out what kind of
hardware configuration I should assemble to get a very reliable and powerful PC under 3000 (max 3500) Eur.

What really matters to me is to know if my current software pipeline will be FULLY supported
by the new hardware and with (I expect) great performance.

As I said, I'm absolutely not a gamer and computer gfx is not my main job, although often I have to produce some piece of
computer gfx (2D and 3D) to use with the software I write or to create some presentation or concept.

Regarding 3D gfx, my works are only relative to visual renderings and not printing or manufacturing or engineering calculation.

So, in short, all I ask to the new machine is to run very very fast and without compatibility issues for this scenario :

1) 2D work in Photoshop CC, Paint Storm Studio and Corel Painter :
All these software have powerful brush engines that leverages on modern gfx cards.
But I can't still figure out HOW, for example, Photoshop CC run on a GTX 1080 Ti. I have found nothing interesting in the web...

2) Will GTX 1080 Ti run Thea Render, Octane, Rhino 3D, 3D-Coat at blazing sped without rendering errors ?

3) Speaking about i7....I have not still understood which one will be better to couple to a GTX 1080 Ti :
i7-7700k for the fastest cpu clock speed per core, or a 6 core 6850K but with lower clock speed per core.

Also, just to consider all the possibilities...I've found an Italian vendor that has in its catalog this PC Tower :
Workstation Computer Wks669 INTEL i7 7700K SKYLAKE 32GB DDR4 SSD 500GB HD 2TB NVIDIA QUADRO P4000 8GB WIFI
All for € 2.598,00.

So again a Quadro ?
P4000 has "only" 8Gb and "only" 1792 cuda, but it's for sure more reliable than GTX...or not ?
PC with a P5000 costs a fortune.....

Oh...What a headache !!

Anyway, thanks again for your help :)

P.S.

Maybe Chipp Walters uses for his daily job a GTX 1080 and could give me his point of view...

See you.