Do you want RGB all over the place? or sober?
Do you want it to be silent? or it doesn't matter?
Do you want reliability? (i think about aircooling vs watercolling)
What I want to propose you (i don't know everything but I trust those parts):
PCPartPicker part list:
https://de.pcpartpicker.com/list/TkkrV6
Price breakdown by merchant: https://de.pcpartpicker.com/list/TkkrV6/by_merchant/
CPU: Intel - Core i7-8700K 3.7GHz 6-Core Processor (€319.90 @ Alza)
CPU Cooler: be quiet! - Dark Rock Pro 3 67.8 CFM Fluid Dynamic Bearing CPU Cooler (€73.99 @ Aquatuning)
Motherboard: MSI - Z370 SLI PLUS ATX LGA1151 Motherboard (€151.68 @ Amazon Deutschland)
Memory: Corsair - Vengeance LPX 16GB (2 x 8GB) DDR4-3000 Memory (€187.38 @ Mindfactory)
Storage: Samsung - 850 EVO-Series 1TB 2.5" Solid State Drive (€287.94 @ Mindfactory)
Storage: Western Digital - Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive (€40.96 @ Amazon Deutschland)
Video Card: MSI - GeForce GTX 1080 Ti 11GB GAMING X Video Card (€1104.99 @ Alternate)
Case: Corsair - 270R ATX Mid Tower Case (€59.99 @ Amazon Deutschland)
Power Supply: be quiet! - Pure Power 10 CM 600W 80+ Silver Certified Semi-Modular ATX Power Supply (€77.99 @ Amazon Deutschland)
Total: €2304.82
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-04-18 15:06 CEST+0200
With that, you are prepared for years to come.
Just keep in mind that prices on graphics cards, memory and storage are awfull today.
Keeping an eye on deals can make you save hundreds of euros!!
Rodolphe.
EDIT :
For the screen, it really depends on you.
Are you sensible to screen tearing?
About color accuracy?
Response time?