I ended up going with Proteus on the Mac since it seems to mirror many of the Trillian Pro features. Thinks like metacontacts, and the ability to sign on to a medium multiple times are things I can't live without now. So, $10 to support it didn't break my bank. Plus, that will get me access to Proteus 3.0, where the interface will be seperate from the actual daemon running the chat services. Think of it like a mini Jabber setup, where you log into your main Mac from any other machine, and receive any messages while the interface was disconnected.

I wrote a PHP script to convert the Trillian buddy list into a Proteus buddy list and should be releasing it soon. It saves the hassle of having to set up metacontacts again, and also having to rename buddies.