If you're headed to Machu Picchu, the best acclimatization is to head to the Sacred Valley (lower than Ollantaytambo), visit (Ollantaytambo (2,792 m / 9,160 ft MSL) is interesting both in the ancient town and in the view of the archaeological zone itself because you can see how it was built, stones that were abandoned on the trail up from the Urubamba Valley, etc.) and take the train to Machu Picchu (2,430 m / 7,972 ft MSL).

THEN see Cusco (3,400 m / 11,200 ft MSL) , Sacsayhuaman, etc. Much better acclimatization schedule, IMO. (The new airport is supposedly to be built in the Valley for that reason, not to mention better density altitude for the airlines - Cusco can be treacherous due to the high density altitude.)

Most farmacias will be able to help - drink lots of water / coca tea (there's no cocaine hydrochloride unless you use a catalyst, and then only small amounts) an can dispense Diamox. Take it easy the first day - unless you know you are fine with high altitude, watch yourself.

Watch out for scammers in Cusco - pickpockets, women and children willing to have their photo taken - but then the woman will say the child(ren) aren't hers and you need to pay the child(ren) as well as her, etc.

If you are there for a while or visit SA, check a membership in South American Explorers (ex SAE Club), with clubhouses in Buenos Aires, Cusco, Lima and Quito and a ton of information online and there about sights, reputable tours, offers Internet, VOIP, luggage storage, events, lectures, etc. (Full disclosure: I am a life member and have been for decades.)

Check the information and contact information for the Cusco VIP Lounge here or e-mail info <at> viploungecusco.com. You can get your oxygen and use the smoking area . (Lest anyone forget, hemoglobin has ~210 time sgreater affinity for carbon monoxide than for oxygen, short enough in supply at CUZ). The lounge (unlike Juliaca) is landside, so no reason, IMO, why you couldn't use it.

I'll be back in Perú later this month - but Lima (with its nasty garua weather at this time of year) and then off to Iquitos and Nauta to catch a river boat for some time in Pacaya-Samiria Natural Reserve / Ucayali and Marañon rivers where they join to form the Amazon.