I would get the Cisco 1841 and then an Asus router for the access point, you would need to learn how to set up NAT on the router. I have a tutorial on the Cisco support forums.
https://supportforums.cisco.com/document/13063251/guide-cisco-router-centurylink
There is one step I am missing and that is to type:
ip route 0.0.0.0 0.0.0.0 dhcp, that is if you are getting a default route from your internet service provider.