I love the way the Sonnars draw as well, and was fortunate to score a beater Nikkor 85/2 a few years ago for a song. It performs really well but is certainly not a compact lens, particularly once the hood is on. And it's heavy with glass and brass.
All feedback on the Jupiter-9s (which I haven't tried personally) suggests that there are a number of concerns, starting with a Contax standard focusing helical and progressing through quality concerns before ending in the intrinsic Sonnar focus shift.
If you want to buy just one lens, and not have to get it readjusted to both your favorite aperture and usual shooting distance, I suggest you go for a true Leica standard Sonnar, such as the Canon or Nikkor.
It may even be cheaper in the long run as the price of a Jupiter-9 is quite a bit up on Jupiter-8s plus you need to expect to have the lens overhauled and recalibrated.
Good luck!