Hi Erin,
Its not going ot be out of the box because Opportunities are going to be 1 to many with accounts and contacts in SFDC. There could in theory be 100s of opportunity owners associated to 100s of opportunities and one contact.
You could potentially create a trigger on the account or contact record that updates fields with "Latest Opportunity Owner"...and then use these details to email the person if you think that conceptually would work.
We do that with a few other random fields for clients that we need to map from the latest opportunity associated to the account. It should work on opportunity owner as well if its necessary.
Cheers,
Michael