Hold the phone, buddy.
You should be able to get internet with dial-up on your Wii, and even play Brawl.
I was able to play my DS online with the USB connector, games like Mario Kart DS and Tetris DS worked fine. Although, there was visable lag in Mario Kart, I was usually able to go through games without disconnecting. Also, I got my Wii hooked up to the internet, and once I downloaded one of the more recent updates, the Wii Shop Channel began working on dial-up, (so it still should.) Downloads and updates to your console take a LONG time, so you may want to download stuff overnight and hope everything goes smoothly.
But the thing is, with Smash Bros., while you may be able to connect fine, and even stay in the game, you will bring with you lag that will cause the characters to blip all over the screen inexplicably, and your opponents will see you blip around like that aswell. So it would be impractical to use dial-up with Smash Bros. But not impossible.
So good luck, I know what it's like to live out of range of broadband, wireless and DSL connections.