I run a WiFi router here that also acts as a hub. Not only do I have Artist MIX and Transport connected(and both work dandy), its a 5GHz dual-band that also allows me to run PT[Control on my iPad(2nd Gen) for more(and remote) control
If you are counting pennies, a simple ethernet switch will handle multiple Artist units(IIRC, you can run up to 4 Artist Mix units for 32 faders)
