Here are some stats for the 08-09 matriculants:
Ponce: median mcat: 21, median gpa: 3.6
San Juan Bautista: median mcat: 20, median gpa: 3.3
Central del Caribe: median mcat: 21, median gpa: 3.5
University of Puerto Rico: median mcat: 23, median gpa: 3.8
San Juan Bautista enrolls the most out-of-state (30-40%), followed by Central del Caribe and then Ponce.
Check their websites for residency info....