At Dive into Ambon your can dive both the traditional muck sites in Ambon Bay, and the sites out of Ambon Bay. We find a lot of critters out of Ambon Bay that aren't found in it.
We dived with Dive into Ambon in December 2014/January 2015 and they run an excellent operation. I can confirm that December is great time to dive there and that there a lot of critters found outside dive Ambon Bay that cannot be found inside it.
I have used the Nauticam 7D and 7D MkII housings. I also used an Aquatica 7D housing for a few months during the changeover from Subal to Nauticam. It had very good handles and I didn't miss having a hand strap while using it.
I used a few different Subal housings over the years (1 x film, 1 x digital and 2 x dSLR housings) and found their hand straps essential as their handles weren't very good and a hand strap was needed to operate the housing one handed. When I switched over to Nauticam housings (i'm on my second one now) I thought that not having a hand strap would be a huge problem. However, I found that I don't need one to use the Nauticam housings one handed and have never missed having one.