Here is the link to Cats International--which has much useful information.

http://www.catsinternational.org/articles/index.html

My two cats (both females) fight because they are both alpha cats. Jealousy does set them off like yours. I use a Feliway plug in to help keep them calm. It sorta takes the edge off their simmering rivalry.

It's supposed to help with the inappropiate peeing, too. If it works, you can buy off an internet site, and it's much less expensive than a retail store.

One last thought: With my cats,the fighting goes in phases. Meaning, sometimes it's worse, sometimes it's better. The older they get, the less they fight.

Good luck to you and your cats. Hope it works out.