Best option: I would suggest reaching out to a local university and asking them if you can get involved in some research projects. However, that's not always practical for everyone.
If I were you, I would go with number 3 and number 1. Number 2 is not going to help you much here because even if they agree to submit one, it will probably just be a generic letter with no real insight. for the number 3s, ask them to talk about your critical thinking skills, problem solving abilities, collegiality, work ethic, etc. Those are all factors that are also important. If you have any experience in data analysis or extended work projects that would be helpful as well.
Since you aren't going to have standout reference letters, be sure that your test scores and research statement is top-notch if you are targeting top 10 universities.
Finally, you can't afford to not network! If you are applying to management programs, you should absolutely put yourself in a position where you are going to meet other academics. If you are lucky, you may develop a strong enough relationship with someone to get a reference letter.
Three suggestions to do this:
1. Attend the AOM annual conference in Boston in August, 2019. Go to sessions/PDWs that align with your research interests. This will give you the chance to meet Faculty/PhD students in the programs you're wanting to attend and it will also help you develop a better research statement and a stronger idea of what your specific research interests are. This is a huge conference and people are pretty busy so it may be more difficult to make meaningful contacts here but it is a great conference to get acquainted with the management field as a whole.
2.Attend the SMA annual conference in Norfolk, Virginia in October, 2019. They have a 2 day Pre-Doctoral PhD Workshop that is outstanding. The applications for it should open up around April (keep an eye on their website: Southern Management Association ).If you can only go to one, I would recommend going to the SMA conference over AOM since it is smaller and easier to meet people. However, there may not be as many top ten schools there.
3. Attend a DocNet Recruiting event: DocNet – Promoting Doctoral Education in Business Throughout The World .