[wrxtasy]

I do like the look of the UI for the MI never been a fan of Apple products, I would have to buy an apple drive, apple keyboard etc I imagine 

So it looks like the Mi Box should do the job if I buy some extras

The Apple TV 4K is Plug N Play which means no need for Keyboards or anything. Only thing it does not come with is a HDMI 2.0a cable.
You have to use home Networked file storage to play your own content with it, you cannot plug in a hard drive.

Be VERY careful about plugging anything into the Mi Box and thinking it will just work. Only buy know working adapters.
And the known working USB3 > Gigabit (Hub) Ethernet adapter is the Ugreen one with the compatible ASIX chipset.

The Mi Box already has Dual band 2.4/5GHz AC WiFi on board, no need to buy anything extra.

Also be aware Xiaomi are about to re-release an updated Mi Box where the only change I believe will be Bluetooth and more buttons on the Bluetooth remote for Google Assist and Netflix.
Existing International Model's - MDZ-16-AB - Mi Boxes (the correct one in your Link) may even drop in price once the new model is on the market.