What I would recommend, is get a wireless router that transmitts the full range, but do the following:

Disable the broadcasting of SSID (and change it from the default), this will make it a little harder for people to be able to locate the network and connect to it.

Enable encryption, and set a strong key for it, and then change the key every so often if you are really paranoid.

I haven't had any trouble with my wireless network, and having others access it, although I have several neighbors who do have unsecured wireless networks, so that may be why.