TP-LINK TL-MR6400 300Mbps SIM Slot Unlocked Wireless N 4G LTE Router.
With 4 ethernet ports. Connect to Broadband for £6 a month with Smarty sim (EE network) or Giff Gaff sim (O2 network).
You can add a Vonage phone for £10 a month for unlimited free UK calls via the ethernet ports.