I will look for potential patients among friends and friends of friends. My relatives are overseas.
The most important criteria in looking for patients would be RELIABILITY. So between an ideal case who is unreliable, and a more difficult yet acceptable case, but is sincere in wanting to help you, choose the more reliable patient. What good would an ideal case be if he/she won't show up during the exam?
There are agencies that "sell" board exam patients but they charge exhorbitant fees [in the thousands of dollars for 6 patients (3 main + 3 back-up) and an assistant]. And, you have to pay in full even before you can look at their profile (radiographs, photos, contact information, etc)!
I am in the LA area.
Hope this helps.