I need a signal boost to my SBC DSL modem, model 1701HG, where do I get one?

I have a 1701 HG modem that is running a computer about 60 feet away. Because of the construction of my building, I need some kind of signal booster to make the wi-fi stronger. Does anyone know if any kind of booster or repeater that may work with the 1701HG SBC DSL modem/router? If so, which one is best?