Hoya wayetii is almost always found in the big box stores in the summertime.  It is a must have Hoya.  Blooms readily, easy care, and adaptibility are all traits for this plant.  It will in all liklihood be mislabled as H. kentiana; so bear that in mind when picking one up.  Here is a time-lapse video including footage of H. wayetii’s blooms opening up: http://youtu.be/qet3YMcW6ok