First, don’t buy what you think you should have; buy what you need. That’s an important difference that can not only save you a lot of time when you go looking for your system, but a lot of money too.
A competent AV salesperson won’t just sell you the stuff he or she sees most profit on, but will take the time to fit your budget with your actual needs. They will ask questions about your viewing habits and preferences, the room you’re putting the equipment in (physical characteristics, lighting conditions, etc) and your budget, at minimum.
Of these, the ability to control ambient light in your viewing room is probably the most important. You might be committed to watching every game as it airs during non-daylight hours, but will that commitment last the month that the tournament runs? And can you say that you’ll never want to watch time-shifted game from, say, a Wednesday on Saturday afternoon? Then, of course, there’s your projector investment and the post-World Cup world.
To be able to use a projection system any time of the day, it’s best that you be able to block light from any windows and doors in the room you want to use it in. If you can’t do this, you’ll be restricted to firing up your projection system after hours. Alternatively, a large flat screen TV might be the better option for your living arrangements.