There are times when it is absolutely worth the money to hire a professional closing agent (I usually do it when I'm paying more than $5,000 for a property and/or if the property's fair market value exceeds $10,000), but when you're buying a property for pennies on the dollar, there are a lot of cases where you can easily close the deal yourself and get by without this added cost.
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!