I know this isn't one of your options, but may I suggest foregoing these newer AF-S lenses and just getting an older manual focus micro lens? I went with 1970's era 105mm F/4 Micro-Nikkor for $275. I bought this from a local used camera shop and effectively paid "retail" price, but you can get this lens for less online. Check adorama.com or keh.com.
The optical performance of this lens is legendary, and is known to be one of the sharpest micro lenses Nikon has ever made, and should do very well for reef photography. Owning a Nikon, you have the flexibility of using most any lens Nikon has produced in the last 40 years.
For reef macrophotography, I think you would prefer to manual focus anyway, so getting an AF-S might not be as useful as you'd think. Moreover, since you'll likely be on a tripod, the VR has minimal upside as well. Other things to keep in mind if you decide to go with one of these older lenses:
- the older lenses are non-CPU lenses and you will have to shoot all-manual, so you'd have to be comfortable with that.
- depending on which body you have (full frame or APS), you have to keep in mind the crop factor because the lenses were designed for 35mm cameras. If you have a full-frame body, then no worries. If you have a body with an APS-sized sensor (like I do), the effective focal length of the lens will be 1.6x what the lens is spec-ed for. All this means is you'll have to move the camera back a few more inches to fill the frame with the same amount of the subject.
- the particular lens I have will magnify up to 1:2, and not 1:1 life size. To do so, you'll need an extension tube. This is probably the one advantage the newer AF-S lenses have over the older micros (in addition to being one-stop faster). The new AF-S lenses support 1:1 out of the box.
But beyond all this, these older lenses will still produce amazing photos. I'm told the used prices for these lenses are actually going up as more and more professionals snap them up for use on their D-SLRs.
Not that the new AF-S micros are bad - they're excellent, but they're also much, much more expensive - with the 105mm AF-S listing at $899.
I also agree with the comments already made. I think the 105mm will have a working distance that will be more usable for taking shots of thing regardless of where they are in your tank.