I know these tools are not Starrett or Mitutoyo, but they work reliably and are economical. I have purchased them through Amazon, but you can buy them direct: http://www.wixey.com/
That one on the left... Can that function as a surface gauge? It looks like it. I'm in the market for one, and I might consider this instead of a traditional one.
These folks seem like a nice little specialist tool provider.