Cleistocactus strausii
The cactus prefers free draining soils, strong sunlight, but not high temperatures — in fact it can withstand hard frosts down to -10 °C. In its natural habitat it receives plenty of water during the summer, but almost none over the winter. In cultivation, watering too much in winter often leads to root rot.
Puya dasylirioides
Puya dasylirioides comes from 2300-3300 meter elevation, where the climate is cool all year. It has taken temperatures in the mid-80s (30 °C), but it's possible that it won't thrive in consistently warmer conditions, especially if nights are warm. It is said to have taken winter lows of 19 °F (-7 °C), and might even handle colder temperatures. It grows well in a deep pot in normal cactus soil that contains no lime. Water it deeply occasionally, and avoid letting the soil dry out completely. Some protection from strong afternoon sun might be needed in warmer climates. Over about 40% humidity is recommended.