I'd be careful about building something for a "computer" which has changed dramatically since I bought a "computer" desk when I first graduated from college in 1996. At the time my home computer was a tower case over 2' tall and proably as deep. The monitor was a monster, taking up proably 18x18" of desk space. My scanner took up a bunch of space as did my printer. And all those diskettes and CD's...
Now our home computer is a laptop about 16"x12" and 2" thick. It spends most of its time on the end table by the couch or on the kitchen counter. The few CD's we have are stuck in a box in a closet--most software is downloaded. The printer/scanner/copier/fax machine is in my office and we connect to it wirelessly.
For work, I've got a laptop, a keyboard and a huge flat panel monitor that take up a bit of desk space but the more traditional desk I have is much more functional than a "computer" desk would be.
(By the way, I say this as someone who invested months building an "entertainment center" about 8 years ago. Now its in our basement because our flat panel TV wouldn't fit and one that would is so small its not even funny. Our new "entertainment center" looks suspiciously similar in basic shape to what was sold as a "console" in the 50's. )