In Gittin 56a-b, we read how the sages warned the Zealots (a.k.a. the Biryonim) to not wage war with the Romans who were holding Jerusalem under siege, but that the Biryonim set fire to the store houses, making war inevitable. Thereafter, Yochanan ben Zakkai faked his death and negotiated with Vespasian, the Roman General and future Caesar, to spare the city of Yavneh and to spare the line of Nesiim -- the family of Rabban Gamliel. Were the sages united in opposing the Biryonim's tactics? Or were there some well-known rabbanim who were known to have fought and died with the destruction of Jerusalem?
Rabbi Eleazar Ben Hanania Ben Hizkiya.
The evidence for this one is not 100% proof, but:
1) In Shabbat 13b it says that חנניה בן חזקיה וסעתו compiled Megillat Taanit. He is also identified as one of the leaders of Beit Shammai, and is known for "saving" the book of Ezekiel among other things.
2) We only have an Aramaic version of Megilat Taanit, but there is a Hebrew commentary (known as the "Scholion on Megilat Taanit"), that is at attributed to at least 7th century CE. You can see an online copy of it here: http://www.tsel.org/torah/megtan/adar.html
The very end of this commentary attributes the megillah to a "Rabbi Elazar ben Hanania Ben Hizkia Ben Garon". Note the difference from the bavli - there's an attached commentary in the link that says the megillah was started by the father (חנניה) and then completed by the son (אלעזר) eliminating the potential contradiction.
3) There is an Eleazar Ben Ananias (i.e. ben Hanania) in Josephus who was famously one of the three leaders of the Zealots during the churban. See: http://www.encyclopedia.com/article-1G2-2587505744/eleazar-ben-ananias.html
Note that he also is the person (according to Josephus) who made the ruling not to accept korbans from the romans -- helping incite the revolt.
Thus, it is suggested by certain talmudic scholars that this is indeed the same person, and R. Eleazar was both a kohen, a rabbi, and a zealot.
See also here for some sources for further links: http://en.wikipedia.org/wiki/Megillat_Taanit#Authorship http://www.jewishencyclopedia.com/articles/10555-megillat-ta-anit
I'll admit this is not 100% evidence, but I submit that this the whole theory is not so far-fetched that it should be completely rejected. We know that Beit Shammai had a bunch of rulings regarding Tumah/uncleanliness of gentiles, etc. We've also got the story of Zecharia ben Avkulus (Gittin 56b), which connects the rejection of a roman korban with the destruction of the temple. The compilation of something like Megilat Taanit might very well be something a zealot might be inclined to write as proof of hashem's purpose. Thus, if R. Eleazar Ben Hananya was a prominent Cohen/Beit Shammai, it's not impossible he that he would have ruled like Zecharia ben Avkulus (as described in Josephus) and would probably have sided with the zealots at least on ideology.
The nassi at that time r' shimon ben gamliel strongly supported the zealots when the revolt began but after when r' shimon saw how bad the zealots were (their hatred amongst each other etc.) he stopped supporting them and was ultimatly killed by the romans as one of the asara harugei malchus
"In those days of oppression, many joined the ranks of patriots who wanted to rebel and fight the Romans. Rabbi Shimon supported them very effectively. Even Josephus, the historian, who generally was not his friend, talks very highly about his great knowledge and capabilities. But Rabbi Shimon did not foresee the tragic results of the revolt which ended in the destruction of the Beth-Hamikdosh. He put all his considerable means at the disposal of the war party because he saw no other way out of the desperate situation. In this policy he was not followed by most other Sages who urged peaceful relations with the Romans."