I think that these are pretty common questions. I had the same ones when I applied.
As for your first question, "are chances of getting a surgical residency slim?" it all depends. MDs are eligible only for LCGME accredited residencies. These are what one typically thinks of as being "MD" residencies. It is a misnomer to call them MD residencies because large numbers of physicians who are not MDs (ie. DOs, FRCs, MBBS, etc etc) go into these every year. DOs on the other hand are elligible for LCGME residencies and AOA accredited residencies (AOA=American Osteopathic Association). ONLY DOs are elligible for AOA residencies and there are AOA residencies available in every specialty from neurosurgery to ophthalmology to family medicine (ofcourse) to pathology. While getting a surgical residency in either type of program is tough, getting one in an AOA program is probably going to be easier. Why? There still exists some discrimination against DOs (perhaps more so in surgical fields than in others). Also applicant pools for DO surgical programs are much smaller, simply because only DOs apply. With this in mind, I am aware of many DOs who have been succesful in obtaining the MOST competitive surgical LCGME residencies. Quite simply, if you decide to go DO and if you want an LCGME residency IT WILL be harder. You will probably have to prove yourself a bit more, some LCGME surgical programs will probably not want you. But it is entirely possible. Getting any surgical program will require you to be at least in the top 10% of your class and score at least 90th percentile on step one of the boards. In this respect, it does not matter if you are MD or DO. If you clean house on the boards and get such amazing grades and are the "perfect applicant," I cannot imagine that many surgical programs would overlook you simply because of your initials. After all, these programs want the best people that they can get their hands on period.
I am not sure what you mean by research opportunities. Most, if not all, DO schools are engaged in some research. As an medical student it would probably be easier to do research at a DO school simply because most people at DO schools have their hearts set on becoming clinicians and could care less about research. This seems to be the case at CCOM, but then again I have never been to an MD med school so I cannot compare how tough it is to get a elective/summer research fellowship.
Another consideration is that DO schools as a general rule of thumb recieve less government funding for research. This is because they have fewer researchers, smaller physical plants, less labs, etc when compared to typically larger allopathic institutions. In summary, research opportunites are probably fewer at DO schools (ie. less choices as to what you would want to study)but there is probably less competition for those slots.
As far as DOs being involved in research at the postgraduate level or DO medical scientists, I think the opportunity is there if you want it. I am far more ignorant about this subject, but you will see (on occasion) articles authored by DOs published in the big journals. One of our professors at CCOM sits on an advisory committee at the NIH. I know of DOs who work at the CDC. These are all things that I have noticed-I can't offer any more than that on this issue.
I think that if you only care about doing heady research or being a surgeon at a big name program, it would be better if you went to a prestigous allopathic school (ie. Rush or Columbia P&S). You will still be able to get to these lofty places with DO after your name, but you will have a harder time. If you want to be an excellent surgeon without being a professor of surgery at Harvard, then going DO will get you there. A big selling point for DO programs for me was the type of "typical student." I know I am going to get flak for this, but after interviewing at lots of programs both DO and MD, I swear to God there was clear difference in the type of student. I found that many (and definately not all) of the people I sat with during the MD interviews were excessively competitive, less mature and much more "airbrushed." On the whole (and again, exceptions exist) DO applicants were a bit more down to earth and more mature.
My advice would be apply to both, visit and interview both and make a decision on where you would be happiest (and where you get in, ofcourse!). In the end I think it matters tremendously how happy and at ease you are with the program, professors and (most important) the other students. Worry about the degree last. If you are destined to be brilliant at what you do, initials will not stop you.
