I don't think many ENTs do BAHA implant surgeries - mine didn't even know what a BAHA was
My BAHA was implanted by my neurotologist - who also did my AN surgery along with a neurosurgeon.
It is not imperative to have your BAHA surgery done by the same doc who did your AN surgery - but obviously, if you use a different doctor, make sure you tell him/her that you had AN surgery. Sometimes the BAHA site "interferes" with the AN surgical site, so he/she will want to know what to expect. It's not a serious problem or anything, but knowing what's inside your head will be helpful to the doc.
There is a list of doctors who do BAHA surgery on the Cochlear Americas website. Go to www.cochlear.com
click on "North America & Canada" then "find a clinic".
Also, if you tell us where you live, someone who has a BAHA might be able to recommend their doctor to you. I have an incredible doctor, but I live in Illinois and that might or might not be convenient for you.
As for dressing changes, there really are none. My doc has you schedule an office visit about a week post op to have the bandage and cap removed; then the next appt. is 3 months later for the processor (assuming your site has healed okay - which is generally the case).
If you have any more questions about the BAHA, don't hesitate to ask. I've loved mine since the first day I was able to wear my Divino