Here are a couple ideas to consider (so many options). I picked Germany on PCPartPicker because you listed a budget in Euros.
Option 1. 7700X build. Notes: The 7700 is only about 7 euros cheaper in this region. not sure why, but for 7 euros difference, I'd get the 7700X.
PCPartPicker Part List
CPU: AMD Ryzen 7 7700X 4.5 GHz 8-Core Processor (€294.89 @ Amazon Deutschland)
CPU Cooler: Thermalright Peerless Assassin 120 White 66.17 CFM CPU Cooler
Motherboard: ASRock B650 Steel Legend WiFi ATX AM5 Motherboard (€220.99 @ Amazon Deutschland)
Memory: TEAMGROUP T-Create Expert 32 GB (2 x 16 GB) DDR5-6000 CL30 Memory (€114.34 @ Galaxus)
Case: Fractal Design North XL ATX Full Tower Case (€169.90 @ Amazon Deutschland)
Power Supply: Corsair RM1000x (2024) 1000 W Fully Modular ATX Power Supply (€174.89 @ Alternate)
Total: €975.01
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2025-01-08 21:15 CET+0100
Option 2. A more "light-workstation"-oriented build with Intel 245k. Notes on this: they just launched the B860 series motherboards, so you might be able to get like a steel legend board or something for cheaper than the Z890, but the prices aren't available yet. This is not the best gaming platform out there and we only have rumors that they may support one more generation of CPU on this chipset, but for many workloads other than gaming, these perform well while still being "ok" for gaming. You mentioned SSE instructions holding you back, and I wasn't sure if there was some kind of workload you use a lot so I figured I'd price this out and it came really close to the 7700X build. If the B860 boards are cheaper, they may end up costing about the same.
PCPartPicker Part List
CPU: Intel Core Ultra 5 245KF 4.2 GHz 14-Core Processor (€279.00 @ Amazon Deutschland)
CPU Cooler: Thermalright Peerless Assassin 120 White 66.17 CFM CPU Cooler
Motherboard: ASRock Z890 Pro RS WiFi White ATX LGA1851 Motherboard (€245.09 @ Proshop)
Memory: TEAMGROUP T-Create Expert 32 GB (2 x 16 GB) DDR5-6000 CL30 Memory (€114.34 @ Galaxus)
Case: Fractal Design North XL ATX Full Tower Case (€169.90 @ Amazon Deutschland)
Power Supply: Corsair RM1000x (2024) 1000 W Fully Modular ATX Power Supply (€174.89 @ Alternate)
Total: €983.22
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2025-01-08 21:10 CET+0100
The other parts for both of these, I left with what you had already selected. I picked a reasonable RAM kit that matches the theme (based on your case selection) and has good timings. Going faster than that shows minimal improvement with Ryzen usually (if it works at all in some cases) and I'm not sure about cost/perf. with Intel either past that.
For the Power Supply: you could save some money on a
be quiet! Pure Power 12 M 850W that'd be fine for your build with some room to grow as well. The
1000W is between the two. The
Straight Power 12 850W is also cheaper than that Corsair and it's Platinum rated.
ASRock motherboards have been doing pretty well lately. I would still stay away from the super cheap models (You can usually tell when the VRM's have barely any heatsinks and the power phases are like ~10 or less). The Riptide, Steel Legend, and Phantom Gaming Nova are usually their best bang/buck options that come with all the important features, but aren't the most expensive models. The Taichi series is great, but still pricey.