What do you need to make a Product Owner:
* A Project Manager, Product Manager or Team Lead with
- 100% ability to build a vision
- 100% sense of return on investment
- 100% market know how
- 50% communication know how
- 50% persistance
- 10% technical know how but 50% technical understanding skills
- 100% courage to prioritize a Backlog and stick to his decissions
If you do not find the candidate with these capabilities, find the second best and let him grow into this position.


I want to add a few more if you don’mind.
Ears that are twice as big as mouth. Product Owners must be able to listen and digest a lot of input from various sources. At the same time be able to form questions that help everyone understand the value issues at hand.
An incredible sense of smell. Much of what a Product Owner has to deal with lies just below the surface of logic and reason. The ability to smell out issues and other things is great.
A knack for putting together ensembles of people to help with the product. (Read Jim Highsmith and then Rob Austin to understand this)