..you'll need an access point that can support bridging or you could wire the AP to the router, as most are router/hubs with 4 available ports. I have the AP hardwired to the lan...which is located in the basement. It was fairly easy to run the wire because I have a drop ceiling in the basement.
However, SpiceWare's suggestion of the Linksys with the booster seems like it would cover your house quite handily and quite likely allow you to sell bandwidth to a neighbor.