When you're buying a property for just a few hundred bucks (which is how most of my deals work) and you're already on a tight budget to begin with, it can be difficult to justify paying twice the amount of your purchase price just to close the darn thing. If you're in a situation where you need to act fast, acquire a property inexpensively and make the closing as easy as possible, closing it yourself may be the most advantageous way to move forward.
You can also look to certain companies and organizations that have a concentration of people that may fall in the above mentioned roles such as investment companies (i.e. Charles Schwab, Fidelity), financial advising companies (i.e. Morgan Stanley, Merrill Lynch). There may be a higher concentration of people who can both afford and want to build their own custom homes or to build income-producing properties. Try linking yourself to financial advisors who may already know of people who have these types of dreams. This isn't a comprehensive answer of all the possibilities but just some thoughts. Good luck!