One of the best places to get bees (and often the cheapest) is from your local bee club. Google is pretty good at finding local beekeeping groups. Such clubs are also a good source of local mentors and hands-on training.
However, when you discuss your hive with others, I would not mention that it is a Flow hive - just say that you are using a Langstroth hive (8 or 10-frame). After all, Flow hives are Langstroth hives, they just use a different extraction method.