Angel List (www.angel.co) is a good resource - people and entities are gauged on their 'signal' rating so you can see who's most active, and that's a pretty good hint as to who is most likely to have leadership/influence in a particular area. You can search by one/many of filters such as Market, Location, Size etc. to help narrow in your search.

It's also worth looking at complementary/competitive companies and have a look at their path and investors - an example would be Pact Coffee in London, or perhaps a chain of coffee shops who have been recently funded such as Philz Coffee in San Francisco?