Help! Who between these people should I ask for LoR?

[Embee]

I'm applying for doctoral programs in Public Health. I have always been good at nurturing relationships with professors and have several options for letters of recommendation, but I need feedback on who might make the most compelling recommendation. 

About me: older student but recently graduated with a BS in Public Health and Human Rights from a HUGE public school with a 4.0 GPA. I've been conducting research in East Africa through several prestigious scholarships. In a few months, I'll be starting a Fulbright in Kenya to continue the same research on refugee health. I'm applying to top-tier schools for my PhD, but my background is very humble/non-academic (and I certainly have huge case of imposter syndrome).

My options for recommenders are: - my academic mentor whom has worked with me for several years and I've taken a graduate course from him as well completed independent research for publication under his mentorship. He is well regarded in the field and publishes work continuously. (Obviously, he will be a recommender for sure)

Choosing between the others is a little more of a challenge.

• my community health professor from community college (who is now the chair of the department). She has always written amazing letters for past scholarships, and she knows me and my work well. However, the fact that she is at a community college may be a negative?

• the lead instructor from a class last semester directly related to my field of study. Although he isn't a Professor, he was a guest instructor from a HUGE international humanitarian organization (think one of the top 3), where he is the director of the health project. I got an A+ in the class however I feel he may not "know" me like other people would.. and we are both gay, if that helps. His name is recognizable to people working in public health.

• my advisor during my study-abroad in Uganda. She is very familiar with my work and current research. It might be nice to have a perspective like hers on my application, however she did flake on me last time I asked her. If I asked her again, I'd be sure to get it early enough that shouldn't be a problem. 

I need three recommendations. I feel like overall I'm a good candidate so I hope I have an application that is impressive enough I can go anywhere I want. I would appreciate any feedback on who I should ask for these letters (or any feedback in general if appropriate). Thank you!

[fuzzylogician]

My opinion, based on these details: your advisor, the CC professor, and the study abroad advisor.

Reasoning: you want letters from the people who know you well and can therefore write detailed letters. It will help to have letters from people who have been through a similar program to the one you're applying to and/or have placed students in such programs successfully; these people will be able to compare you to their other students and have an informed opinion about your ability to succeed in the program. The CC prof has written strong letters for you in the past and knows you and your work well -- all positives. Bonus points if her knowledge of you is current, not to do with things that happened too long ago. 

If possible, you want someone to discuss more than just your grade and work in one class. For these reasons, I would say the second option (lead instructor of a class you took last semester) is less of a good choice -- he's not a professor, and doesn't know you as well, so can't write in detail about you.

Finally, having people discuss both your classwork and your fieldwork sounds ideal, given what I assume you'll discuss in your SOP and given your interests, so again that would be another reason to prioritize the study-abroad advisor over the lead instructor from the one class (but maybe he can be a backup, and extra letter whenever you're allowed to go over the 3-letter requirement and submit an additional optional letter). 

[Embee]

Great feedback @fuzzylogician, thank you for offering your perspective! Im leaning towards asking my advisor in Uganda, particularly as I'll likely see her in person next month when I'm there.