I rode from Cuzco to LaPaz but honestly, I found the ride a bit boring. It's always nice to be cranking and we did a side trip to Amantani on Titicaca which was great. We picked up a boat in Puno and stayed at a guest house on the island and a wicked electrical storm blew up over the Lake so it was one of those magical nights. You'll be on asphalt the whole way and there are no major passes. Most of the trip will be fairly flat altiplano riding under 13,000ft so I would not worry about soroche. Yes 2-3 days should be enough if you are reasonably fit. Don't get me wrong, it's a nice ride just not exceptional. Nice old ruined churches in Juli (not Juliaca)