I have the mediator 1200pci and i think it's great =)
I have been running it for about 12 years now.
You don't need a gfx card if you use an old 10Mbits network card but the rtl8139 driver need to use the gfx memory to function.
I have expanded my amiga with: Voodoo3, nic card, sound card & usb card and everything functions just fine