For a setup like this (250k monthly visits, mostly content + images, and a peak of ~350 concurrent users), I wouldn’t jump straight to a large VPS.
In most cases, performance here depends more on optimisation than raw server size—especially proper caching and how media is handled.
A reasonable starting point would be something in the range of:
- 2–4 vCPU
- 4–8 GB RAM
- NVMe storage (important for WordPress + image-heavy sites)
If things scale or you want more headroom:
For providers in Europe, you could look at options like Hetzner or OVH depending on budget and preference.
Also worth noting: a well-configured cache layer (and possibly a CDN for images) will often make a bigger difference than moving to a much larger VPS.
I’d start moderate, optimise first, and scale only if you actually see resource limits being hit.