You will not be able to play in the same game on Battle.net unless you manage to get two external IPs from your provider. Not exactly your question but it might prove useful once you get a better internet
connection.
Both of you will need to be patched up to the latest version and you will each need your own copy of the game complete with a unique CD-Key.
Use the UDP setting when creating games and make sure your firewalls have exceptions for StarCraft..
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