We did a trip to MAPI and the Galapagos last year.
If you are looking for a hotel in Lima we stayed at the Country Club which was very art deco and absolutely delightful.
We had the oxygen pumped when we were at the Monasterio and this made for a much more peaceful sleep. Apparently this makes breathing comfortable for the next 24 hours or so. Anyway we felt great after this and the light headedness didnt surface until our drive to Cotopaxi and only after 15,000 feet.
Miriam