well I will happily look with you. It sounds like a pretty tall order.

Holboellia fargesii - This is an evergreen vine that blooms early spring and will handle full sun and zone six. If there is more than one plant present it might even produce fruit.

Holboellia latifolia - This is pretty much the same as the one above but is rated as zone 7.

Passiflora caerulea 'Alba' - This evergreen is said to be "free flowering". I'm not exactly sure how to interprete that.

Solanum crispum 'Glasnevin' - here it is full sun, evergreen, blooming from April to November. Ok not quite zone 8. But if the place you want to plant it is near the house I've hear you can add one zone to your rating.

I hope something here helps. It's all I could find.

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