In the clients I have worked with, the buzzword I'd use is "alignment". Alignment between your organization and this prospective CEO, in terms of values, vision and execution.
Assuming for a moment that you'd only look at experienced people that have some level of skill to speak of, think not of who they are, but of whether they can make your company how it should be.
Thus the common pitfall is 'if they succeeded with that other company, they'll do well with this company too!'.
That is often not the case.
Most startup CEOs have a mix of failures and successes - not all of which were in their hands - but true lasting success between CEO and company only happens when they have a revitalizing effect on existing strengths and culture in your enterprise.
Happy to talk more at length if you'd like !
I believe it is critical that the candidate has an extensive "inside/outside" network in the industry. The outside network that will allow her/him to connect you business with people and leads.
A CEO will be able to work and learn the industry, is very flexible, and can adapt very quickly. It is the personal skills that are often missing. I have worked in global markets all around the world, traveled extensively in Europe, Asia, Middle East and South America. What companies often do not have is the CEO who has the touch and personality to meet people and immediately connect.
The CEO that can talk about the product all the way to the small details is not a CEO that I would recommend. These are the tasks for his second line in the company. The CEO needs to have the interpersonal and leadership skills. Great places to search are conferences and networks, platforms like these, where you can connect and get a feel for them.
Let me know if you would like to discuss this topic further.
Generally you can look for someone:
1) Who have the ability to motivate and inspire people to "want" to get things done.
2) Able to think strategically to crystallize on how to move your company from where you are to where you want to be.