Dual Internet Connections?

Let me explain what I am trying to do. Currently we have a single fractional T to connect to the internet. We want to add a second T that only 1 or 2 computers will use for a bandwith intensive application. What would be the ideal way to setup the network to accomodate this, also, the PC needs to be on the current network as it needs to access those resources as well so a seperate network is out. I would also like to use my current firewall so as not to have to license a second one. Any suggestions would be appreciated.

Thanks,

Bill