Thanks. Now I know I'm not the only one interested. The blueprint has the question, should there be one output or two? Could such a thing be selectable? Two mono outputs, the same as playing a mono record on a stereo, has the advantage of using a stereo amp as two separate mono amps. One speaker points one direction, the other speaker connects elsewhere, and the volume of each can be adjusted independently. Using my own sound system for big car shows, I've used two speakers on poles to the west lot, two more on the south lot, and each lot is adjusted independently of the other. Yet, using this same sound system, there are times when I can set two speakers on a stage in an auditorium where stereo is beneficial. I can do this without any rewiring (2kw amp is in a portable rack, with equalizer and other hardware).
The advantage of a single output would be the ability to use (mono) headphones on the other channel, on a laptop using its internal sound card. Personally I have yet to use headphones -- I use them constantly with vinyl for cueing, but for CD's and computer I've never bothered. So my vote is, if it has to be one or the other, I'd go with two identical outputs.