From what I have found in my own attempts is that the only thing you really need for a render farm (assuming you're using the function in 3Ds Max to do it) is computers capable of running 3Ds Max (preferably with the primary computer being more powerful).
Other than that, it should be more a matter of numbers to increase performance, the more computers you have, and the better they are, the faster it will go.
Now if only my team had more than one computer that can actually run 3Ds Max (and only version 7 too...).
