Probably the two most common ways to build a Brown defense are Kings of Judah or Kings of Israel. You can also do Brown splash, utilizing characters with strong abilities like Gomer, Uzzah, The Jeering Youths, Complainers, etc. You can also splash these characters into a Kings of Judah/Israel defense if you want to make a larger defense.
I personally think Kings of Judah represent the best Brown has to offer. Gates of Jerusalem offers drawing and CBN abilities for its characters, something no other protect fortress does. They also get "Instead" protection with Solomon's Temple, although you'll need to commit to a certain offense with ST. There are many powerful CBN enhancements, such as Haman's Plot, Scattered, Gib Trick, and Dungeon of Malchiah (played on King Zedekiah), as well as many strong negates like Stiff-Necked, Shimei's Curse, Wickedness of the Tenants, Korah's Rebellion, and Achan's Sin. And Wickedness Abounds can draw you 4 cards.
As for Broken Cisterns, there is obviously a fun combo with it and Stalks of Flax/multicolor GEs, but I wouldn't call it mandatory in a Brown defense.
