Besides the Bible is there any information on who Og, King of Bashan and Sihon King of the Amorites were. I do not trust wiki. They do not seem to be in the Catholic Encyclopedia. I know their names occur often in the OT. Do you have sources you trust?
Our knowledge of Sihon appears to come solely from Biblical sources, so you already know your answers there.
As far as Og goes, he is found in the Midrash: Talmud Bavli Zabahim 113b; Pirkei D’Rebbi Eliezer (Heigar) “Chorev” Ch. 23 ד"ה וזה אשר תעשה; Yalkut Shimoni, Torah, Parashas Noach, Remez 55 ד"ה זכר ונקבה יהיו; Yalkut Shimoni, Torah, Parashas Noach, Remez 56 ד"ה ד"א ויהי לשבעת; Yalkut Shimoni, Job, Remez 926 ד"ה +לט+ התקשר רים. Talmud Bavli: Berachot 54b. Possibly offline sources; not sure these will help you much.
The online source wise-obs.tau.ac.il/judaism/jewish_astro.html may not be so reliable in itself, but provides a bibliography at the bottom.
Some of these works may be by Protestants. There are a lot of Biblical scholars out there like that.
I assume you are looking only for factual accounts. There is poetry and novelization here that I will elide.
Here are all the biblical references to Og, and subsequently, Sihon: quod.lib.umich.edu/cgi/r/rsv/rsv-idx?type=simple&format=Long&q1=Og&restrict=Old+Testament&size=First+100.
Haydock Bible Commentary has some information you may find useful. Scroll down to verse 11: haydock1859.tripod.com/id496.html.