It makes sense to complete the AOW
before the speciality courses - as the AOW dives are simply Dive #1 from the corresponding specialty courses. That means you can 'credit' those dives if you subsequently take that specialty course (negotiate to save money).
For your AOW, include the PPB, Nitrox and Photo as your optional dives. Then, when you complete the specialty courses later, you'll be able to skip the first dive - which
should mean you get a healthy discount on the courses.
It's important to select the right instructor to deliver your courses. The instructor's motivation, experience and breadth of knowledge on the subject is critical to ensure that real development can be made. Some tips:
1) PPB - Whilst
any instructor can provide this course, many won't have a high level of competence in helping you develop excellent buoyancy, trim and weighting. Scary but true. Ideally, look for an instructor who is 'tech qualified' and willing to transfer that knowledge into helping you improve your recreational diving core skills. Alternatively, if you aren't bothered about a 'PADI card' - opt to do a 'Fundies' type course instead... that's far more beneficial and takes you to a whole other level of competence.
2) Nitrox - There's not much to teach on this course. You can do it online and just finish the cylinder analysis task in a real dive centre. If you do opt to take it as a 'classroom' course, then find an instructor who's willing to add extra value. There's lots of relevant stuff that can be added to a 'basic' nitrox course, such as; basic blending/compressor intro, precision dive planning and gas management etc.
3) Photography - Again, any instructor can 'sign up' to teach this. I recommend that you investigate potential instructors carefully - be prepared to interview them. If you're going to learn photo - then you need to have an instructor who is highly experienced and capable at underwater photography. Ask to see their 'online gallery'. Ask them how many photos they've had published. Ask them what photo competitions they've entered. Ask them what their 'style' and 'preferences' are. Basically, the instructor should be an avid photographer in their own right. Any avid photographer will have galleries, styles, preferences... and should have
It's a sad (and for many students...shocking) fact that instructors don't need to possess any significant experience or competence to teach these specialty courses. Those that don't will just regurgitate the contents of the (wafer thin) manual and take you on what is essentially a glorified set of fun dives. You need to be very selective in choosing an appropriate instructor, if you desire to make real progress in a specialty area.
I posted more relevant info to your question on this recent thread:
PADI's Course Rush