It is the spiral Aloe - Aloe polyphylla an endangered, alpine species
from high elevations in Lesotho. As if the spiral arrangement of the
leaves weren't enough, the candelabras of pale yellow tipped, soft red
tubular flowers on mature plants are extremely handsome. It is
occasionally available from Cacti and succulent specialists and I
understand that Pan Global Plants in Glos. usually have it in stock.
Pan Global's url is http://www.panglobalplants.com