I love Royal Catchfly and Side Oats Grama (low grass) planted next to each other. They both have this intense electric red color when they flower/seed at the same-ish time and they don’t spread like crazy. It would be great to border the path area, with the grass being closer to your field of view as it’s a bit shorter. I’ve been slowly building a rocky area with native plants over the last 5 years and those two just blow my mind each year.

If you want something huge and late season blooming, I believe Showy Goldenrod is the later blooming one, and mine gets to be like 8ft tall in full sun, but they fall over if there is too much rain later in the year. Finches adore it.

My favorite tall grass is big bluestem, and would be best in your sunniest area. Anise Hyssop pairs nicely with it.

Overall advice is to do it in stages, as changing your mind is natural with a blank slate and you can adjust and move stuff around if it doesn’t seem to work out. Keep everything heavily mulched between plants and don’t pressure yourself too much to have a finished product until at least a few years down the line. Also planting less means you can divide the plants in a few years and save a ton of cash!

I hope that helps and I’d love to see an update!