I am a fixed screen guy so I can't answer your question about the screen, however, the upcoming Epson 8500UB is claiming 120,000:1 contrast. I would really wait and see how it stacks against the JVCs in reviews.
Honestly, after using the Panasonic PT-AE3000U and the JVC DLA-RS2, I much prefer the picture quality of the JVC, but the Panasonic is dead silent, and the JVC is way too loud for my taste, to the extent that I will probably be looking into building a hush box for it when it is time for a permanent install.
That said I know the JVC-RS10 and RS20 and their soon to be replacements the HD550 and HD950 (don't know the RS version #s) are probably quite a bit quieter than the RS2/RS1. Also keep in mind I have to run things with the high altitude fan speed on and the JVC is much louder in high altitude mode than in normal mode, and my current mounting solution does allow some extra vibration.