I would recommend applying to all 6 programs and once you find out which one's you got into making the decision there. Do it soon b/c many programs are filling up fast. I am pretty sure anatomy is almost filled.
You will not necessarily have an easier time getting into med school from say, anat. The students that go to that programs are generally the best students and they are ranked. So you may be a great student but be ranked relatively low in the anatomy department and have trouble getting into med school. With that said, the anatomy program from what I gather, did have the best sucess of any of the programs this year (in terms of getting thier students in). They consistently perform this way. The head of that program, Dr. Leichnitz can be a great asset and will help you a lot. You will also get a decent amount of exposure and face time in the phys department. Biochem, Genetics and Micro departments will not give you very much help at all. You will pretty much feel like you are on your own in those programs. To tell you the truth, if you do well, the grades will speak for themselves. Other than guidance, the faculty of each department will not do a great deal for you so you won't really miss it.
I did the biochem. program and did very well. I got in to VCU medical school despite a very low undergrad GPA (2.8).
In terms of preparation for medical school, the anatomy program will do that the best. All 6 programs take the physiology and biochemistry classes. The Anatomy program also takes histology and neuroanatomy (in the 1st and 2nd semesters) while the Phys program takes cardiac physiology in the second semester.
Biochemistry, by far will give you the most leeway in terms of classes you take. They only require you to take the biochem course both semesters and mammalian phys in the first semester (plus a 1 hour semenar each semester). So you can take any classes you want to and tailor you courses to what you want to take (not what they make you take). Anatomy and physiology have essentially set course requirements.
Regardless of the program you pick, it will be very hard. There will be a noticable step up from undergrad. I would recommend you treat it like a job: 4 hours of class followed by 4 hours of studying in the library and then go home. If you do that, you will do well. The tests are really easy if you know the material. The problem is that there is a rediculous amount of material and it is hard to get through it all. There will be a difficult transition in the beginning. Just make sure you study your butt off for the 1st exam. A lot of kids were slaughtered by the first exams. By the withdraw deadline 1/3 of the class dropped out b/c they were failing or near to it.
MAKE SURE YOU GET PRACTICE TESTS BEFORE EACH EXAM. From year to year the exams don't change a tremendous amount.
In general, I would recommend the biochemistry program. It gives you the leeway to pick your schedule and if you choose, you can take the classes many student in the other programs take. Take 12 credits the 1st semester: 2 seminars (both are gauranteed A's), biochemistry and mammalian physiology. Get a 4.0. The admissions committee only sees your 1st semester grades b/c they end discussion on candidated by March. Make sure you do well in the 1st semester. You will have an advantage b/c a lot of people will take 15 credits (an extra 4 credit class w/o the 2nd seminar) and will be struggling through thier transition period. The Phys program recommends 15 credits while the anatomy program requires 16 credits in the first semester.
I talked to Dr. Heldberg (dean of admissions for the medical school) to see if I should take more than 12 credits. She told me that the admissions committee does not care how many credits you take provided you get A's in the Biochemistry and Physiology classes. Ironically, to them a person who gets A's in phys biochem, and the 2 seminars (4.0 w/ 12 credits) looks better than someone who gets A's in phys, biochem, 1 seminar and a B in 'drug dependence' (3.7 w/ 15 credits). They both got A's in the major classes but one got a lower GPA due to the extra class. The extra stress of the extra class does not pay.
If you have questions post 'em or private message me.