Most of the echeverias I get are from the big box stores; they seem to have enough variety to usually start a small collection. The local nurseries or those further away may have specimens not usually found in BBS.
Here's an echeveria from Young's Nursery that has an online store for ordering but I drove up to their location and found this Echeveria which I've never seen in any of the BBStores.
Echeveria setosa var deminuta:
