Ya'll are being WAY to pessimistic.  If the guy has funding, paying a programmer isn't going to be an issue.

Here's how I hire qualified programmers on the cheap.  It works well and I have a track record of putting together solid teams that can deliver on time and under budget.

First make sure you actually do have a budget of some sort.  Any programmer willing to work for a percentage stake on a serious project is not someone you want to hire, period.
Second make sure your legal bases are covered.  This means talking to a lawyer and finding out what your actual liabilities could be in the area you are operating in.  This is especially true in the western world where we're all a bunch of litigious bastards.  I've found it to not be such a big issue in Central America, but here in the States and in Europe, you'll be sued into oblivion within a week of your first press release if you don't handle the legal issues first.

Third don't hire a programmer, hire a project coordinator.  Someone with a track record.  You can find them on LinkedIn.  They'll be the guy/gals hanging out in the PMP and Project+ areas and they'll have a ton of references posted clearly on their profile.  What's a ton?  At least 10 glowing reviews.  20 is better.  Anything more than 25 is probably someone who paid for it and not worth your time unless you can verify the people endorsing them are who they actually claim to be.

Fourth, once you have a detailed project plan look at all the technologies involved.  More than likely each tech will have a definitive open source project that sort of serves as the defacto-standard for what you're trying to accomplish.  Look at the list of contributors.  Github is a good way to see who's been up to what.  Find someone with recent commits to the repo, or pull requests that have been accepted in the last 90 days.  Don't pick the #1 guy/gal they'll be consulting and they will charge a small fortune.  Instead pick someone from somewhere in the middle up the top 10%.  They are interested enough in the tech to be playing with it in their spare time and have gotten good enough to make an impact.  All while probably not being compensated for it.  Their compensation demands tend to be minimal, although you may need to work them part time.

Approach them and offer cash money to work on your project in a similar capacity.  Do not offer equity!  If they want equity they will ask for it, but don't think you're going to get the next Satoshi Nakamoto or Linus Torvalds for straight equity.  In fact you'll be lucky if you get the next Leeroy Jenkins.

Doing this one wierd trick has given me a track record of 0 project failures and only 2 late deliveries in 10 years of IT Consulting across a broad and diverse range of products.