setting up a wireless home network

I am planning to upgrade my home wireless network. My DSL Modem is old. It is a 2WIRE Home Portal 1000HW, which i believe runs at wireless B speeds. I need to run my DESKTOP machine wirelessly since it is so far from my phone jack. I have a LINKSYS wireless B adapter now, and would like to go to LINKSYS wireless N. Do i need to upgrade my MODEM to a faster one? for instance a 2WIRE DSL Gateway Model 2701HG-B?