I would recommend that you use serial instead of UUIDs. Why are integers preferable to UUIDs?

• They occupy less space. This is a marginal consideration in the base table, but a bigger issue for foreign keys.
• Integers are easier to read and remember.

In many databases, tables are physically ordered using primary keys. In such databases, new inserts on a UUID will almost always go "between" records, which is expensive. However, Postgres does not support clustered indexes so the underlying data is not ordered.

There are downsides to integers:

• There are a finite number, although big ints pretty much solve that problem.
• They encode order-of-insertion information. Actually, this can be a positive or a negative.

Other than space usage, I don't think there is much harm in using UUIDs on a static table. I strongly prefer integers, only resorting to UUIDs in situations where an integer would be difficult to calculate.