I would say the "best" ones are Devolo magic ones.
https://www.amazon.co.uk/devolo-Magic-2-2400-WiFi-next/dp/B089185YD7/
Mind you I wouldn't pay ~£280 quid for that "iffy" solution. You should get a good a Mesh system to cure your wifi woes. £100-170 will sort it forever. Or there are even cheaper solutions that may do it for you.
--------------------
John
--------------------
I do not work for VM. My services: HD TV on VIP (+ Sky Sports & Movies & BT sport), x3 V6 boxes (1 wired 2 WiFi,) SH2 in modem mode with Airport Extreme Router +2 Airport Express's. On VIVID200, Talk Anytime Phone, x2 Mobile SIM only iPhones.