For the truly intrepid, I would look into automating this in AE. You can set it to import, add the bug, render, etc. automatically through your batch. Also, if you have cs5 than it should be able to utilize more than 4gigs of RAM.
If you did get a 2nd computer, then you could set it up like a render farm using AE.
This might need a custom script, I don’t know. I’ve never automated something like this.
Good luck.