Hello,
The easiest way for you and your brother to be able to play on a dynaverse together would be to trade in you router and get a 5 port switch (hub). Ask your ISP how many Ip's they'll give you for what you are paying a month. Usually it's 3. Plug the main internet into the hub get some cat 5 cables and connect your other 2 computers to it and away you go. You'll both be able to play cause you'll have separate Ip addy's. You'll also have to set up a couple new e-mail accounts.
The only advantage to a router is the additional protection it provides via firewall's etc........unfortunately this is also it's downfall. A hub is less secure than a router, but you can always beef up your system adequately enough on your own.
At least this is what my wife and have done and we've never had any trouble.
(and yes she plays SFC3 with me! LOL
Respects,
Nemico
Galactic Foreign Legion