I've read through your post and you seem to be on the right path. I think you should keep #4 mandatory, if at all possible. Also, while you can look at the design of an amp and maybe point yourself in the right direction, in the end the amp has to stand on its own 2 feet with regards to sound quality. Some amps have 4 rubber feet. Thats OK too. Just as long as it sounds good.
I've had several Pass amps, the McCormack you mention and an old Boulder. Never had a Plinius. Also, I think its safe to say that a newer Boulder amp would sound much different than the old one that I had. Given all that, the first amp I would recommend you look at is Ayre. I feel their products are state of the art for SS. That doesn’t mean that you will like them, but to not consider them would be a mistake. Generally speaking a lot of people say that they are analytical. I don't believe that’s an accurate description. Ayre does pass a huge amount of detail through their products but its the cleanest, purist, most liquid solid state I've ever heard. In my main system, I have 2 V5's biamped vertically powering my speakers. Depending on how big your room is and how much volume you need, 1 V5 may be all you need. I won't lie, though, 2 is better.
"I can get BOULDER products but they are WAY high priced." By that statement, I take it you live somewhere near boulder. Ayre is made in Boulder as well, so there should be no problems there.
If it turns out that you don't like the Ayre for some reason, I highly recommend you listen to BAT. In my opinion, they are in the same league but they do sound a little different. Their SS sound falls somewhere in between Pass and Ayre.
One last thing. The weight issue. Are you kidding me? Its not like a girl that you have to go around and be seen with. You need to suck it up on that one. Pay some to move it or through your back out. This is your audio system were talking about here.
