Its simple really.......
Just go and get a adsl router with 4 port hub.
then set it up, connect your broadband line to the right socket on the router, and then connect your old system using the ethernet socket and your new system the same way, then you have internet access on both of them with another 2 ports spare for any extras.
Ps. dont go for d-link or bt. THEY ARE CR*P. always getting problems
Simon