I bought a D-Link DAP-1360 Indoor Wireless N300 Access Point off Takealot recently. It has multiple options, like Access Point, Repeater, etc.
I configured mine as a repeater. It allows you to connect to your existing WiFi, so no cables are needed. Afterwards, I logged into the repeater and gave it a manual IP address, afterwards i logged into my main router, and modified the DHCP lease range to exclude the IP Address below... Now I have the same SSID throughout my house, and the devices switch seamlessly between them.