First, here are some inspirations:
I saw this tutorial on two-tone biker jackets,
But if you can't shell out two grand for the real thing, or don't want to destroy your jackets, Forever21 and H&M has these sleeveless trenches, it'd be a great idea to wear them over a leather jackets. Both to save money and give yourself more flexibility during the course of the day. You can also wear them over T-shirts or shirts for a more casual look. I got this at F21 for about $35, I think with the varieties of looks you will get, this is well worth it.