1st you will have to check the fibre map to make sure it is available in your area.
Please use below links to check the map and how to install Fibre:
Afrihost will provide you with a Wifi router to use however as you have indicated, the wifi signal will have to be boasted to accommodate your infrastructure,
you will need to add one or two 3rd party Wifi booster/access point around the house. Wifi boosters are available at your nearest computer retailer.
If you require further assistance,
please visit our Help Centre: https://help.afrihost.com/
or see our FAQ page: http://faq.afrihost.com