I would advise against the IKEA 'made for computer' desks: they won't take the weight, even if they say they will. You're better off getting something like a dining table from IKEA, as not only are they bigger, they will take the extra weight.
Alternatively, you could do what I did and go to a furniture auction. I got an great antique desk for £10, plus £10 for a chair to go with it. It looks groovy with a modern Mac sitting on it
yes he's only looking at dining room table systems from them