On connecting 3 HDV cams onto a MAC

[Libelulau]

Hello everybody!
I am designing a workflow in which I need 3 cams onto a MAC, there the video is mapped through mad-mapper, then it goes to a Anycast Station (AWS - G500) to finally be projected live.
I found two difficulties when trying to put the pieces altogether:
-I need to connect 3 Z5 HDV cams to my G7 MAC with Mac OS X.
That is one thing I am not achieving to do, could you assit me on that? Is a firewire hub enough?
-How can I connect my MAC to the Anycast Station? We cannot make them recognize each other...
I do hope you can shead some light onto these issues I have!!!

Thanks in advance