Hi @jimmyvixen ,
The below link should give you some guidance on picking the best one for your needs and the model numbers should allow you to purchase from any good retailer.
https://www.tomsguide.com/uk/us/best-wifi-extenders,review-2225.html
Those devices rely on WiFi traveling well in your property and not too far from your router.
If you know that WiFi signal travels poorly in your property, or that the distance is quite large, you can additionally look into powerline adapters with WiFi functionality at one end.
The disadvantage with this is requiring two devices instead of one. Devolo is a good brand, others are also available.
Good luck! 🤓
