I'd tier your approach from the perspective of highest confidence in the candidates.
First go to your personal network. Linkedin/Facebook, friends/colleagues/family, tell them generally what type of person you're looking for. 80% of hiring comes from networking for many good reasons. If someone you know can vouch for a candidate then you should have a much higher level of confidence they'll work out.
Second, go to forums/blogs/meetup groups...within the vertical you need. Be careful about your qualifications though. Sometimes the best prospect may come from a different space so don't completely shut that prospect off unless you feel that's a no go. But also talk to companies within the space who might have contacts interested.
Third, broadcast more generally. Craigslist, forums like this one and others.
Be real clear upfront about the equity part of this. I've seen many folks do a search and not let someone know until they're interviewing that it's an equity position. I don't like that approach.
Best of luck,