Finished MA in different discipline, applying for PhD in psych

[Philpony]

I doubled in psychology and philosophy in undergrad (at a well-regarded but SLAC), then finished my MA in philosophy at a large state school with a very good philosophy program. I was a good student in undergrad, but I was a much better student as a graduate--I presented at conferences, have a 3.98 GPA (darn single A-), won an award for academic work and contributions to the department, etc. 

This year I plan on applying to both philosophy and psychology (clinical/counseling) PhD programs this year. I have two questions.

1) should I use my philosophy thesis as a writing sample? It is psych-oriented, but more interdisciplinary, but by far my best academic work. Or should I find a more traditional research paper from undergrad?

2) should my LORs all be from my advisors from my grad school, who will no doubt write me very good letters but are philosophers, or should I get LORs from at least one of my undergrad psych profs who haven't worked with me in two years and would write good-but-not-as-good letters?

Any other advice for someone who has been out of the discipline for two years?

Thanks in advance!

[Clinical]

1) No, submit a research paper.

2) Get letters from at least 2 people in the field. Preferably all 3.

Are you applying to funded programs? Do you any research experience in psychology? With no research experience, I wouldn't apply to any clinical programs. And without experience in research, counseling, or something similar, I wouldn't apply to counseling either (though I know much less about counseling programs).

Clinical is really tough. It is expected that you have research experience before entering a program. Assuming you don't have research experience yet, if you really want to end up in psychology, try to find an RA position before you apply. Very few professors (except maybe at for-profit schools) will be willing to risk taking someone who is new to psychological research. They also won't want to have to have to train them from scratch. I don't mean this to be harsh... this is just how it works, and you will likely be competing with people who have a lot more experience. Good luck with whatever you decide!