You will need a static public address for the router you want to connect to. The access-list can be modified to allow a connection from anywhere even though it's less secure, but if it needs to be done, then it needs to be done.
Does that make sense?
Also, please post a config of the remote router if possible so I can make sure your commands are right.
BTW about the SDM... I think you'll abandon it soon after seeing it... it doesn't do what it's supposed to all the time, it adds bunches of lines to your config, it messes stuff up, and frankly it just plain sucks. I hate it. It's never caused me anything but trouble. I think it's the only GUI tool I've ever used that's actually harder to get things accomplished with than a command line.
Cheers! Let me know!