My personal advice: don't bother with extra computers/monitors (ie. TVs)/video games. At least until you are comfortable with the pace of cadet life.
Do you need more distractions than facebook and the rest of the internet?
Some people can handle it, some people can't. It certainly isn't worth worrying about now. I never bought a TV, never got into video games, and certainly didn't have an extra computer.
Go to basketball games. Go to hockey games. Go hiking. Go skiing. Go to Haps/Back East/O'Malleys/Dublin House with your friends when you're 21. Explore Manitou. Much more rewarding distractions than an extra computer. I was able to fit that stuff in and double major. You'll spend enough time at the Zoo doing homework.