I met with another GC (a very good friend who does only large projects) yesterday who agreed with all of you that we need to bite the bullet and rework all but two of the seven steps so that they are of equal height. He liked the longer landings rather than lots of stairs bc of the curve, because this is outdoors and esp since we don't want railings. He advised that lower riser heights of 6 1/4 inches are better for natural gait when you have longer treads in between. So, out of the seven steps we currently have, we will eliminate one in the middle completely, keep the existing 6 1/4" riser at the top and the existing 6 1/4 " at the bottom and install a series of 2 double risers 6 1/4 high by 14" in between with landings. We will have to regrade a little, especially the 10 feet of the final part of this walkway (before the final step onto the firepit patio) to raise it up 3 inches, but it can be done with a shovel. He said he's doing lots of concrete + brick walkways and patios and saw nothing wrong with my original idea (copied from Houzz - in case you guys don't know that web site, it has thousands of photos for everything to do with residential design) of brick borders with concrete in the middle. He did advise me to match the depth of the concrete middles to follow the same lines all the way up, which hadn't occurred to me. I've managed to get $400 back from the first contractor who did the original steps (it really should be more, but my friend told me do NOT try to get these first guys to come back and do a better job. He said they clearly did not know what they were doing) and my OTHER landscaping contractor who built the firepit patio and retaining wall said he will fix it on the weekends for $600 provided I pay for materials. At this point, the only materials I need are bags of concrete and some more crusher run for raising the base of the 10' walkway. If you have suggestions, please feel free to detail them. If you are merely going to be critical or caustic, please don't bother. I could probably stick those solar lights in the ground for now to give us some lights along these steps.

These are pictures of the house should that help as you consider both options for us. Note: Top steps are stone and walkway/bottom steps are both currently concrete.

In warmer climates as SoCal and Texas, travertine works well outside..covered or uncovered. I have travertine on my patio that is open to all the weather elements. Here in Texas we have winter 2 months out of the year and it might dip into the teens or 20s. No issues with my travertine that has been installed for several years. The travertine that is installed in the photo is a versailles pattern (also called a french pattern). Looks like Durango travertine but could also be called Crema Imperial, Ivory or Classic. Several names for just 1 color. Being that you're in SoCal, most likely the cost of travertine is highly expensive. You can find glazed porcelain tiles that mimic the look but may not have all the sizes. Pricing may also be better. Visit actual tile showrooms to look around and get advise. Avoid big box stores as Home Depot or Lowes.

Yardvaark - You are absolutely correct. I had originally gone through that process with every intention of rebuilding the steps as they were (depending on the contractor, that meant brick + concrete, or brick + stone since the original steps were not 100% reproducible). I decided on a brick contractor due to his ability to source matching bricks, and also his incredibly fair price. It hasn't been until recently that I've re-opened the can of worms of whether or not I really want the front to be rebuilt to match the original, rather than using this opportunity to make some changes. Another reason for not committing to a design before a contractor is because, for me, budget will always be a factor in whether or not a design element is worth it. I don't know how much a design detail will affect the overall cost until I talk with the contractor, and that often affects whether or not it becomes part of the final plan. In the case of the brick contractor, the difference between having a contractor willing to work with angled buttresses vs. not was $15,000 vs. $5,500. Since I don't plan on living in this house forever, I'm more concerned about ROI in the long run vs. having something built to perfectly fit my personal preferences. I respect that everyone has a different threshold for different design decisions, and I love getting to see the results of that!