You could do a mix of Sedum album, dasyphyllum, anglicum, hispanicum, and lydium. These are all small ground cover type sedum. I would think by using them all you would find which fit the site the best, as the hardier ones would flourish and the others die out. Having a mix might also add to the visual interest, especially if you place path stones.
All of these bloom and are evergreen.
There may be others that would work also. Lets see what others come up with UrbanWild.
I love your idea.
