2 Internet Connections 1 Network

I need to set up my office so that we have 2 ISPs, but one network. I need the server to access the internet through our T1 line and I need the rest of the computers in the office to access the internet through a dsl connection while at the same time stay on the same network. what is the best way to set this up. Currently, we have a T1 line that is supposed to be reserved for the server only. It is connected to a Sonicwall PRO 2040.