As far as I know, and have only briefly looked into wireless ADSL (mine is all wired) you would be able to do what you want with an ADSL Modem Router.

Something like the NETGEAR DG834G would be perfect for you. It's a typical 4 port modem router (ie, plug the phone line directly into it and it has 4 wired ports (ethernet RJ45 cat5 cable) to connect to PC's to provide broadband internet to). It also has a WAP (Wireless Acces Point) built in to allow you connect to the modem via wireless connection.