If you have dual quad Xeon 3.0ghz+ cores with 32 gigs of RAM and a workstation 3d modeling video card.. you're pretty much set.

Is no need to upgrade. the time increase would be so insignificant it would go unnoticed.

If u want faster renders. You need to check into render farms. Or dial up a service who has renders farms and make business by rendering for people via internet service @ a slight monthly fee.

If u have those specs you listed, and ur frames are taking a minimum of a hour. I WANT TO SEE A FEW RANDOM FRAMES OF YOUR WORK!!! XD