Hi Brandy, thanks for reaching out! Most of the deals I close in-house are vacant land, so there isn’t much work involved with contractors or improvements. If I were you, I would probably bring this kind of deal to a title company or closing attorney, simply because they’ll be able to handle the moving pieces a lot better than you can on your own (and the cost should be reasonably low – low enough to justify the value they’ll be bringing to the table).

Negotiate the price with the buyer and finalize the paperwork. Once you’ve decided on a purchase price, you can write up your contract. Free contracts can be found online or you can contact a real estate attorney. Some states also require additional paperwork, such as a land disclosure form, so be sure to do your research before completing the transaction.
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!