Wifi assistance needed

Can anyone help,

I moved to a new house around 6 months ago. My family and my mother in law.

I'm from the U.K. And have BT Fibre 56mps Download and 18 Mps upload.

I'm using the most current Bt home hub and the wifi only covers the fist half of house.

When we moved in I hard wired all the rooms with cat 7 10gbs cable for all streaming devices and games consoles.

I'm using a 1 gb switch at the moment( the wife didn't want me to spend £500 on a 10gbs switch) just yet.

They all work fine and by doing this removed a massive load on the wifi network.

Now the easiest answer to this question is move the Modem/ router.

Sadly I can't it has to stay where it is and I have to find another solution. ( for those with evil mother in laws you'll understand)

Now where I have the switch located in the house I can run another cat7 cable and fit a device to the ceiling as I have easy access to the rafters running above it. So my question is

What type of wifi device do I need.

The best one I think would work is

Ubiquiti UniFi AP AC LR Indoor Access Point

Is this the right sort of device we have around 20 wifi devices running when we are all at home and with little to no signal in the living room (lounge) or kitchen. Any tips hints or general help would be appreciated.