Oh my! I wasn't familiar with any of those, so I looked them all up, and am totally personally smitten with Temptation! Aptly named! The others, while beautiful like all passiflora, were more common looking, I thought. But I have absolutely no information about rarity, so I suppose, in the end, follow your instinct *lol* But I personally would buy the Temptation. Here in California, it's not an issue of how hardy, but how to keep them under control! I have p. exoniensis (my favorite), molissima, giant granadilla (which could possibly become a favorite if I could get the dang thing to flower....), citrina, lavender lady, sunburst, biflora, sanguineolenta, and caerulea. Have seeds to others, but haven't sown them yet!
Amanda 'romando'

Hi Melanie
Temptation is beautiful but is prone to mildew in our climate.
Purple Rain or Violacea should both be fairly hardy, Purple Rain being more so without doubt. Best time to but is Spring.
Myles

Myles - Many thanks for that, I hadn't considered that mildew would be an issue. I'll probably get Purple Rain for outdoors for now, then. :)

Amanda - Wow, very envious of your collection! I'm gradually trying less frost-hardy ones, as caerulea and Constance Elliot are still growing despite plenty of frosts. I definitely agree that Temptation's gorgeous - will see how it does, might have to keep it indoors though!

Melanie :)