We visited SA (and walked the Inca Trail) last April...
Fellow AFFer,
KPC had recommended going to the Sacred Valley as soon as we arrived in Cusco and I am glad we took his advice.
I pre-booked a taxi online through
Taxidatum to meet us at Cusco Airport and take us to the Sacred Valley. They even offer a senior discount!
We had arranged to drop our luggage at our Cusco hotel for storage on our way through and just took small bags to Ollantaytambo (it is difficult to wheel luggage along the cobblestone streets although a lot of the accommodation places seemed to have little wagons to meet the taxis and buses in the main square).
Our B&B,
Kamma Guest House was perfect - it has recently been refurbished, is run by two lovely girls who completed their hotel training in the US and breakfast on the roof overlooking Ollantaytambo was a highlight! The location was excellent and they even provided walking poles to help you get around the nearby Inca sites.
We caught the tourist bus from Cusco to Puno and stayed a night in a hotel in the centre of town. On arrival we shopped around for a 2 day/1 night Lake Titicaca boat and homestay tour leaving next day and it was a bargain!
Look at doing the Andean Explorer from Puno to Cusco as it is often substantially cheaper in that direction. The train trip was a highlight and was so luxe.
I wish we had time to go to Bolivia but we'll have to leave it to next time... Our daughter and her fiancé agreed that Bolivia was their favourite country during their recent 6 months of travel in South America.