I have a Motorola surfboard conneced to a RP614 router, which is like fifty bucks new I think. I supply internet access to my entire house with about 8 roomates. I highly recommend this netgear router. It has a configuration page where you can easily, and I mean easily adjust what mac address your isp will see, and if your pingable, what local ip's you can assign or dhcp out for your computers etc. Being able to filter services, or ports etc, and with the ability to see all attached devices on your network, current ip config info from the service provider, anyway it is very handy - even emails you with log info should something happnen. Anyway, I really like it and all the people in the house get amazing speedy internet access - 100 and it seems/feels like you are the only one connected to the cablemodem. Just wanted to give you my experience, and hope this rambling post gives you a helpful perspective...
Oh yah, I believe you can have up to 255 connections (with hubs etc of course).
Good luck with the USB stuff
There is no reason for any individual to have a computer in his home.
President, Digital Equipment, 1977