As a Soldier of Bureaucracy, it is important for you to have a computer system commensurate with your position of importance. It doesn't matter what you use it for, but it needs to be as large and powerful as possible so that everyone that sees it knows how important you must be.
Chances are good that the only thing you'll need a computer for will be writing presentation slides for meetings nobody attends, surfing the corporate benefits site, and watching hilarious cat videos on YouTube. Nevertheless, you need people to be awestruck with the size of your system.
Ideally, you will have a laptop. This allows your importance to travel with you. You can take your awesome system to every meeting, meal, and bathroom break, enabling you to impress more people in the company in this way. A suitable laptop will be one that is roughly the size of a small yacht. You may need a small team of Sherpas to carry it around the building for you, but this will impress the masses even more.
Regardless of whether you have a laptop or desktop system (or, even better, both), you will need a computer display in your cube. It is not good enough to have a monitor just large enough to show an application or two. You need to be able to run at least ten applications simultaneously, all completely visible at once. How else could you see whether anyone has sent you a critical meeting notice or forwarded jokes to your inbox at the same time as you're watching another "America's Funniest Dog Videos" episode and doing a refresh on your FaceBook site to see if you have any friends yet? For this reason, I suggest you forego a typical computer monitor and instead request a large-screen television, preferably 60" or larger. This display will dominate, or even overrun, your desk space, proving to everyone around you just how busy you must be.
To ensure proper operation of your system, you may want to have the IT department construct raised flooring in your cube for the extra cabling or cooling ducts that could be required. You won't ever need these capabilities, but you want people to think you might. Also, that extra few inches boost will raise you above your peers and give you the ability to see whether your bosses are in their offices, probably waiting anxiously for a visit from you and your amazing laptop.