-D is an option to OpenSSH to set up a SOCKS proxy. I didn't realize that existed until just now. Anyway, if you're not using OpenSSH on the local side, then it probably won't exist.

I'm guessing, though I have no low-level experience with AIM, that it might be trying to make other connections beyond the initial connection. That's a guess based on the symptoms you've presented. If that's true, then you'll have to find an AIM-specific proxy. You might also want to try using the TOC AIM protocol and see if that works. I think it's an option within GAIM.