That's a tough problem, regardless how you approach it.

The best thing is to know a lot of people and just happen to know somebody who can help you. The second best is to scour the internet and your network for people who are good at what they are doing. Trying to hire your first person on a job board is probably the worst thing you can do.

Rather than start with a position, start with the person and figure out how they can help you given their skills and personality.

This is not the time to standardise your positions, you have to make best use of the flexibility that startup setting provides and use that flexibility for your advantage.

You will have to give them a lot of freedom anyway.

Don't hire people who can't deal with ambiguity and/or need a good precise description of what they are supposed to do. Most of the work is defining what you are supposed to do so you will be getting very little value out of them if you have to provide all of the direction.

If you are starting with a vision and try to force somebody into that vision then you are already fighting an uphill battle.