>>168572
Have you checked craigslist? There's always someone selling cheap computers on there. For specific models the HP Z workstations are pretty swag and the Fujitsu towers look nice if you can find them, but an Optiplex with an i7 or even a core 2 duo will work in a pinch. You're going to be updating stuff anyways so you might as well get something that's cheap and easy to update.