You realize that this thread is going on 10 years old?? And the other thread you resurrected is 8 years old. The conversations have died down. You have a pretty plant. How about starting a thread?

Of the ones you mention, the hydrangea will likely work the best. Any flowering plant needs sun to bloom heavily, but vines which are more adapted to shade conditions - like the hydrangea - will grow and look better even when not in bloom. For something less common, look for Holboellia or Schisandra, both shade loving flowering vines.

I have a Florida Seiboldi that I keep in a large pot. It is not very hardy to my zone (6B). So I bring it indoors into my kitchen every winter. It flowers inside the house even during winter time. I also have another one (name I forgot) that is kept in a large pot on the deck. Never bring it inside. It puts on a spectacular show every year. Both have been in the pots for over five years now. I toss in some new compost and some alfalfa pellets each year. That is just about all the fertilizing they get apart from the pruning.

Jay - couldn't this be Late Lilac (Syringa villosa) or one of the Preston Hybrids? I think they're more commonly grown than S josikaea.