What could be a better solution?

Hi,
I have joined a company last week and this is what i found out..
adsl modem
Dc with 2 nic(also acts as a sql app server too for the local clients and remote database for branches.)
Ex 5.5 With 2 nic(!!!!!!!)
2 Cam servers with 2 nic’s
1 Novell 4.11 for old dos based app.
and finally one static ip.

so everybody is connected with the lan and at the same time with the internet too. I hate this setup and i want to fix this… any suggestions?