Candidates for Ashkenazi Chief Rabbi:
David Stav, National Religious, the most liberal and secular-ish candidate, endorsed by Yisrael Beytenu and Yesh Atid
Eliezer Igra, National Religious
Yaakov Shapira, National Religious, son of former Chief Rabbi Avraham Shapira
David Lau, ultra-Orthodox, son of former Chief Rabbi Meir Lau
Possible candidates:
Incumbent Yona Metzger, National Religious but sympathetic to the ultra-Orthodox
David Yitzhak Grossman, ultra-Orthodox, the candidate most disliked by the National Religious community
Candidates for Sephardic Chief Rabbi
Incumbent Shlomo Amar, ultra-Orthodox, there is a law pending to allow him to run for a second term, he'll be re-elected
Possible candidates:
Shumel Eliyahu, National Religious, one of the few prominent National Religious Sephardic rabbis.
Some background articles:
http://www.haaretz.com/news/national/race-for-chief-rabbinate-marked-by-byzantine-politics.premium-1.513336http://www.haaretz.com/news/national/yesh-atid-endorses-david-stav-for-chief-ashkenazi-rabbi.premium-1.507247http://www.haaretz.com/news/national/religious-zionists-vie-for-post-of-israel-s-chief-ashkenazi-rabbi.premium-1.504738