Access Point for a network

Hi,
I’m trying to make some laptops and computer clients wireless on my network. My building has 2 floors. I’m looking for the 2nd floor to become wireless. It’s approx. 700 ft in length. and width.Eventually I would make the first floor wireless. But this will not happen for a while. I guess my question is can anybody recommned a good access point? One that I can build with for the future. I’ve seen a belkin that is good for 1800 feet. Would this be a good solution? I’m fairly new to this. Any help would be appreciated