A:
I would suggest just an extender.
Maybe the "Netgear Universal WiFi Range Extender with Ethernet port".
Or the "Amped Wireless - High Power Wireless-N 600mW Gigabit Dual Band Repeater and Range Extender" if you want to extend a 5.0Ghz Signal"
Your not necessarily going to find "one thing" that will give you a ton of range, unless your willing to spend a pretty penny for it.