I am currently reproducing your cabinet as I was looking for a good widescreen cabinet to build. I was curious if you can provide photos of the rear of your cabinet. Would you mind either posting them here or in a pm to me. Hope to hear from you soon. Here are a couple of pics of my cabinet:
I'm flattered you are making a cab like mine - you're going to love it! One thing I wish I did is drill holes on the side for pinball flipper buttons (it's on my long todo list right now...).
Below is a pic of the back of my cab - it's a little dusty. There are 4 items in the lower right corner: power button, coax for antenna TV (it has a tuner), optical audio out port (to attach to a 5.1 channel surround system), and the power port.
You can kind of see at the very top a vent with the same material as the speakers and the computer vent (also on the back side - it's the large mesh square on the bottom rear panel). Both were made in the same way as the speaker grills, but I didn't paint the wood black (I figured no one would ever see the back, guess I was wrong!).
Let me know if you have other questions. I usually check back on the forums once ever 2-4 weeks.
Congrats, your cab is looking awesome!