Hi forward25! You know, us NP's always tend to say in these threads that it is important to know the job market in your area before planning your future advanced practice nursing field. But I think, in your case, it is different. You know exactly what field you want to get into and you are probably willing to relocate in order to get to do the job you want. Is that right?
I just have a few opinions to pass on. Both schools
you picked have excellent reputations as far as training in community health - I'm sure you already know that. Although UCSF's program seem to match your goals a bit more, the program prepares you for a CNS role. You should realize that as far as having prescriptive authority, clinical nurse specialists are not able to obtain the authority to write medication scripts in all 50 states. Also, while NP's in general have prescriptive authority across all the states, some if not many, have provisions for physician delegation or collaboration.
I would be inclined to pick the ACNP route if I am in your shoes. This is because most ACNP programs I know of (mine included) allow a greater degree of flexibility in individualizing the clinical portion of the program to meet the student's career goal. If your interest is in HIV/AIDS, your program can arrange clinical rotations that are specifically for this field. On the downside, I would like to point out the limitations of an ACNP certification as far as treating the pediatric population, unless of course, the NP is dually-certified in adult and pediatric ACNP. In addition, the ACNP role tends to be viewed as a purely in-patient NP role by some (meaning, the training is specfic to hospital-based medical management). This is not true of all ACNP's as some do have out-patient roles in addition to in-patient management.
Good luck to you and I hope you get what you are after with the degree you end up picking.