If you are looking for an all-around lens, the best I found for a crop sensor Nikon is their 16-85 behind a dome port. I have the large modular dome and the 16-85 worked great while using my D90. I could shoot fairly wide (effective 24mm) and could zoom very close. The lens requires a +4 diopter.
Still don't understand why the 40mm lens won't focus close while UW. Never used the lens, but lots of experience with 60 and 105 says it should focus nearly the same in the housing as it does on land.
On a crop sensor camera, I prefer the 60 to the 105 as there is an appreciable difference in depth of field. The shorter distance to subject also helps when vis is not crystal clear. When shooting really tiny stuff, the 105 is the right tool, but for most fish photos and even nudibranch photos, the 60 is the clear winner for me.
Now that I'm shooting full frame, the 105 has become my primary lens. I have not found a comparable "all-around" lens like the 16-85 that works FF.