I did my nitrox cert immediately before my AOW (like an hour before my first AOW dive), that way I was able to dive nitrox on all my AOW dives and not use a elective dive specifically for nitrox (although if i recall correctly there was no required nitrox dive - just the course plus demonstrating the use of the gas analyzer).
I wanted to do AOW to experience deep diving with an instructor, plus to improve my buoyancy, trim, and general diving skills. The cost was just about the same as paying for 5 regular dives, plus I got a private instructor.
I did PPB as my first AOW dive so I could apply that to all the remaining dives.
While it was required to do deep and nav, most of my AOW dives were deep anyway. The way I managed it was to talk with the instructor after my first (PPB) dive about the things we agreed I should be working on to improve my overall diving skills, and regardless of what we called the dive (I did wreck, ppb, deep, nav, and boat) we just worked on making me a better diver. All the dives were working on my buoyancy, the last 4 were deep, all were boat, all were nav (took the compass with me on all the dives), and we worked on all of that same stuff on my wreck dive. So it really didn't make a difference what electives I chose. And in the end I came out a better diver, and that's what I was looking for. If you take that approach you don't have to be too concerned with what electives you take. I figured that concentrating on a more focused set of skills was more useful that getting a brief intro to a few different things.