reply to kracksmith
Re: inherit 2 VoIP phones need router 2600-series obviously, but way EOL.
The newer 2800 series and slightly older 3700-series routers will also do this.
Module-wise, you can look at this list here, for Cisco Voice/WAN Interface Cards for analog lines -- as cramer noted, pay attention to the difference between
FXS and FXO and get card(s) accordingly.