Just added some aries 3 stainless steel side rails. part number 202015-2. they were $190 delivered from amazon. be aware that while you don't have to drill any new holes in your highlander. You have to make modifications to the brackets that come with the side rails. Megahurtsss documented this under the DIY running board section page 2.
I had to use bolt cutters to modify the front brackets and a 1.5 inch metal bit on my drill to modify the back brackets.
Took me 5 hours to do one side and the 30 mins to do the other. Small learning curve there!

The info on this forum helped me a ton with adding my side rails.
Good luck with the side rails. I love the look of them on my magnetic gray highlander!