Sounds like you will need a pre/pro at least. You might luck out if both your DVD player and HD CB have DVI, you could use an extron, of more likely a Gefen DVI switcher for the video... you could hopefully use the TV and a decent universal remote to switch video into the TV (X Box doesn't have DVI yet, likely never will).
The audio is tougher, you could do something like I said, and deal with the video that way, then just get a remote control 2 channel pre amp and use it to switch the audio, again this setup will require a decent universal remote... not anything extreme, but say a harmon at least...
The audio is tougher, you could do something like I said, and deal with the video that way, then just get a remote control 2 channel pre amp and use it to switch the audio, again this setup will require a decent universal remote... not anything extreme, but say a harmon at least...