I don't know if they have espresso cups but I got a set of cappucino cups from CircaCeramics. They're really good quality, and sturdy. They sell on etsy but I bought them at an art show. They're very nice people! If you don't see espresso cups give them an email, they might just have some.

For better photos of the cups go to www.circaceramics.etsy.com. This photo is pretty much just an excuse to show off the dog!

Good luck with your search!