Interesting...
Happened to do this just about an hour ago.

Got x3 of the network cards for $11 shipped with cables even.
so when you use MiamiINIT, I just typed in networks/3c589.device
(Assuming you left the install put the driver where it wants.)
And after that everything seem to setup automatically. Just be sure to uncheck the Printer thing towards the end, and let MiamiINIT save the file.
Go in Miami, and then load the settings from the MiamiINIT v3, usually it saved it as miamiinit.config.
Hope this helped.