If I got a PCI board, would I be able to use a network card in it so that I can connect the Amiga to my ADSL router?
yes of course. I have a 1200 with old Mediator 1200 with Voodoo, Sb128, Tv card and an ethernet card for networking (file share and ADSL). Infact i have ADSL 256 kb on my Amy :-)