The other thing is that this will be a cabinet with wooden doors that will remain shut. Heat build-up could be an issue. Is there a "standard" way to insure you get enough air through the cabinet to keep everything cool enough?
Kinda weird replying to my own post, but the cabinet maker had a suggestion about the heat build up. He said we can put a small fan inside the cabinet that only comes on with high temperature. This sounds like a reasonable solution as long as we can dump the hot air somewhere outside the cabinet.
Also, it looks like we are going to divide the cabinet vertically so that I will have the sub to the right side of the vertical divider, and all the components (Blu Ray, receiver, etc etc) on the left side with shelving. I could probably line the sub woofer enclosure with something to deaden any vibration. This vertical divider will make it more difficult to deal with the plate amp unless I put the amp on the front of the box, pointing out. The only thing is the plate amp is almost as wide as this box is going to be so it could weaken the box. I liked the idea that the amp came on and off automatically, which is one reason I veered away from Isiberian's suggestion of using a separate amp. Also, I wanted to save space by using the plate amp. But now, maybe I can find an external amp that also comes on automatically? I'll have to just add another shelf for it on the left side.