I used wireless router Asus RT-N66U (but any will do), and two TP-Link TL-PS310U for the XTI.
The I-Techs connect directly to the router
The TL-PS310U comes with the drivers and a little software that must be installed
Then, it's a matter of building the network, which basically consists giving the correct IP to all the amps, PC, router and TL-PS310U's, in my case:
Subnet mask:
255.255.255.0
IP:
192.168.1.1
192.168.1.2
192.168.1.3
192.168.1.4 etc,etc
I made proof that all this works, but haven't finished the installation (still finishing the Custom Panels and IPad panels).
I hope this helps you, any problems I'll be glad to help (that's actually my job here in Portugal

)
NOTE: One thing I noticed and that might interest someone is that with passive USB hubs you can connect 4 XTI to each TP-Link TL-PS310U, but I used one active USB hub and this hub was counting as one device, meaning that I could only connect 3 XTI if I was using this active hub.
EDIT:I can already foresee a problem in my installation, every time you turn on the PC you have to open the TP-Link TL-PS310U software and activate (connect) all the USB devices it sees (The XTIs). Since I'm using Kiosk mode on S.A. and want to give access only to Custom Panels, I don't know how to automate that USB activation at startup, but I'm sure I'll find a way...