The 802.11n wifi technology signals have greater range due the advanced MIMO antenna technology allowing it to penetrate indoors up to 230ft and extend outdoors to a wifi range of 820ft in the best working environment.
The 2.4GHz wifi range travels farther through walls and solid objects because of its bigger wavelength allowing it to connect with wireless enabled devices at greater distances, however it operates on the same frequency as common household electronics causing interference.
The 5GHz signal wifi range is a much shorter, because it has a hard time passing through walls and objects; however this frequency range is not used by many electronic devices making it free from most electronic interferences.
The - D-Link DIR-655 N+300 Extreme-N Gigabit Wireless Router
It's priced around the $60.00 range, and has excellent range and performance!
You get great information about this at: http://www.wireless-home-network-made-easy.com/wireless-access-point.html
TIP: For best performance results when using a Dual Band router, try connecting all your high bandwidth intensive equipment for streaming video and music in your entertainment area on the 5GHz band, and have all your computers connecting at distant wifi range to the 2.4GHz band for accessing email and html pages.