The only physician-scientist residency that is AOA credit is a neurology program that is dual ACGME and AOA accredited
http://www.physicianscientists.org/careers/training/residencyhttp://www.physicianscientists.org/careers/training/residency
http://www.physicianscientists.org/careers/training/residency (this list isn't the end-all; there are definitely more)
Here's the skinny: academic medicine, and specifically basic research oriented academic medicine, isn't as popular as you might think. It's possible to be trained at an allopathic institution and to ultimately open a lab at an allopathic school. How often does it happen? Probably not that often, but then again, osteopathic medicine is not geared to nor does it seem to care about basic research. If you want to go into research, you need to be proactive. Do research in the summer after your first year, take a year-off after your second or third year to do a pathology research year or spend a year at the NIH (either through the NIH professional student program or through the HHMI Cloister program, although the Cloister program has existed since 1985, they just took their first DO student this year), and try to schedule a research elective during your third year. Another option is to do an extramural PhD through the NIH, although you don't need a PhD to have your own lab. When it comes time for residencies, it is essential that you enter a university-based program. Many programs will be more than happy to find time for you to pursue research, but an even better option, if you can get in, is to enter a physician-scientist residency since these pathways maximize your research time. After residency/fellowship, you'll be able to post-doc in your field, and although you'll primarily be in lab, depending on the university, you'll also have time in clinic. After your postdoc, you can start your own lab, assuming you can find the funding

. I should also mention that the NIH funds field-specific postdocs at several, but not all, institutions.