Well if you are planning on a farming settlement I would say look to an area with high grasslands as those will probably be your best bet for finding a kingdom, naturally I like many others would self promote my kingdom. But alas as I am far in the north I am not what you are looking for.
As for the kingdoms that do fit your desires for being a farmer you would probably want Alesia, Borewall or Fortuna as I believe those are the kingdoms who contain the grasslands biome.