In general, the research oriented school. A PhD in clinical is basically a research degree - research experience is FAR more important than clinical experience when you're applying to PhD programs, especially ones that focus equally on research and practice, and the more research-oriented programs (e.g. Clinical science).
If you're looking at a practice oriented PhD (rating of 2-3 or lower in grad guide to clinical programs book) than it would matter less.
If you're able to get quality research experience at both places, then it won't make much of a difference. The most important thing will be your scores, your research experience, LORs, and fit with the researcher/program when you apply later.