Photoshop CC 2017: new hardware

Hi there,

I signed up here to discuss the topic "hardware and Photoshop CC 2017 with you.

First, sorry for my not so perfect english, it's not my native language.

I am using Photoshop CC 2017 and I am doing composings and matte paintings mainly.

My files are often 4000 x 3000 px @ 300 DPI @ 150 - 200 layers with lot of smart filters, clipping masks and adjustment layers.

The PSD files are sometimes about 2 GB in size.

My recent hardware is too weak for this amount of data:

CPU: AMD Phenom II X6 1055T (2.80 GHz)

RAM: 8GB DDR3 RAM (1333 MHz)

GPU: AMD Radeon HD6870 1024MB GDDR5

SSD: 128GB

HDD: 500GB

Especially when zooming and using tools like clonestamp or brush tool, there are heavy lags.

Merging layers is no option for me as I am a big fan of non-destructive editing in PS.

Now I am planning to buy new hardware, but I'm not so sure about the CPU und RAM.

The i5-8600K is strong for Photoshop, even in comparison to the i7-7700K or i7-8700K.

I got a lot of information from https://www.pugetsystems.com/recommended/Recommended-Systems-for-Adobe-Photoshop-CC-139/Hardware-Recommendations

On the other hand the i5-8600K is often titled as a gaming CPU and has no Hyperthreading.

If I had to choose between a i5-8600K and a i7-8700, which one would you buy?

I am not so sure about the RAM, too. Is 16GB DDR4 enough for my project sizes or shall I upgrade to 32GB?

A quote from  Puget Systems:

The exact amount you need will depend on exactly what you are doing, but based on your document size we recommend a minimum of 16GB of RAM for 500MB documents or smaller, 32GB for 500MB-1GB, and 64GB+ for even larger documents.

I would love to hear your recommendations. What hardware do you use and how do you handle big project sizes in terms of hardware performance?

Thanks and kind regards,

Mike