The iiyama GB3480WQSU offers a standard 3440x1440 va panel with 1500R curvature, up to 180Hz refresh rate via overclocking, alongside adaptive sync and a claimed 4000:1 contrast ratio... all for £340.
If your devices only support up to 4K at 60Hz, a "premium high-speed" HDMI cable (18Gbps, HDMI 2.0) is perfectly fine. Again, just avoid really old or thin cables. Early HDMI cables (HDMI 1.4 or older ...