Good question about what is less common to me. I would generally say if it's unlikely to be found at Flower World. (large nursery in our area). But I wouldn't limit myself even to that. I liked all of your suggestions. Good variety of color, flowers and foliage.

I have always though of the saxifrages as shade plants. Can they grow in hot sun that is good for roses?

This location would be good for some peonies as well. Preferably with strong stems such as Henry Bockstoce. We recently purchased a tenuifolia fern leaf peony from Far Reaches, and i would call that an unusual peony/plant.

If I had more sun, I'd consider Betony. BTW, Zone 7 is halfway to tropical.

Betony looks interesting. Thank you. Tropical? Hmm, Are you from Alaska? We've had trouble growing plants that are supposed to be good in zone 7. Every Hebe I've tried. Meant to ask GG if the Hebe she suggested is cold hardy. We regularly get down to 10 degrees. We used to grow a Chilensis Gunnera, but after the second one failed to come back from winter, gave up.

One of the whipcord hebes may be worth a try, having the smallest leaves of the bunch.

Ours did OK for several years and made it through some teens.

This hebe looks interesting, except this is not a xeriscape bed as many of the main items will need watering.

https://xeraplants.com/plants/hebe-ochracea-ec-stirling/

Hebe 'Red Edge' is one of the hardiest - should be good to the bottom of zone 7 :-) The whipcord forms are good, too. And not particularly xeric plants - they appreciate a good soak in summer.

The saxifrage is one of the more succulent forms and will take PNW full sun easily. And is evergreen!

junior, you may be underestimating your hardiness zone. How close are you to Maltby/Flower World? Unless you are significantly east of that and up in the foothills, you should be an 8a or 8b like the rest of the Puget Sound basin.

We are at 400 feet and up against the foothills. I've recorded temps as low as 9 degrees. We also seem to be in a bit of a chilly micro climate. We always have snow on the ground long after it's disappeared fro most folks.

We have several nice patches of both the variegated and nonvariegated saxifrages in shady areas. Good to know they can take some sun.

If I plant any of the Whipcord hebe's in this bed they'll get regular watering. We have an irrigation well and as I've noted in another thread, watering is a form of entertainment for me. :o)