Hi tiny,
Im new also, Have you ever tried Thyme between stones? There are many varieties and are very sturdy for walking on. Some of it even gives off a scent when stepped on.I just bought some that has gorgeous texture.
I also love sedums for between rocks.The low growing sedums spread but can be easily controlled because they are shallow rooted.
cyn

I am in the process of putting in the exact same type of patio. First, make sure that you have a combination of soil and sand in between your stones or you won't be able to grow anything. Also, it is important that whatever you plant gets watered regularly, especially the first couple of years.

I am going to plant wooly thyme on mine. It is very hardy, fast growing, evergreen, likes full sun and gets pretty little purple flowers in the summer. It only grows about 4" high, very compact and is drought tolerant. It really doesn't have a scent.