Bob,
Don't you think your going to lose sound quality with solid state? It has been my experience that tube amps deliver punch for lack of a better word. I have noticed that in a band setting the solid states just don't deliver the same sound. Warm, headroom, growl, etc. Have to agree the weight issues are tough to deal with. One of my amps is a 1969 Marshall 50watt with a 1968 cab loaded with original greenbacks. There is no solid state that can deliver that sound, on stage, however, it is a royal pain to move around and to much power for your needs. I also have a 18watt deluxe reverb clone that Andy K made from an old fender bassman combo. We put a emminence 12 legend alnico speaker in it. Light weight, sounds fender, has punch. Don't give up that classic tube sound.There has to be options like that out there. Jody, I think the real weight in tube amps is the transformer, especially the older ones and ceramic magnet speakers. The chassis as you mentioned could be a factor. By the way I do think the line 6 is a great amp, by itself. When on stage against any tube, it's weakness will show. It is also my opinion that the line 6 and other digital equipment is better suited for recording than the difficulty of micing an amp. Just my humble opinion. I hope you find something that pleases you.
Dan