I would rent a car in Salta. Drive down Hwy 68 (drop dead beautiful) to Cafayate. Spend the night in Cafayata. Drive up Route 40 to Cachi. Just north of Cachi is Hwy 33 (I haven't driven this but understand it is also incredibly beautiful) back to Salta. Either direction works. You won't find a more beautiful 2 days unless the road from Moab Utah to Brice Canyon through the Escalante and over the Hogs Back through Capital Reef to Bryce canyon. Both should be on your bucket list.