I would echo FDog's advice; think about the system as a whole -
BUT I would take it another step or two further.
If you are going to buy a mirrorless camera, you are buying a
system. And that includes lenses, ports gears, tray/arms and strobes. The camera is going to end up being the least expensive part of it - and the part you are going to change out in a couple of years. You want to think about where you are going to be then in terms of what you can reuse and upgrade and what it's resale is going to be like.
The Sony Nex5N is a great camera. There are very good wide angle options for it behind a dome port, and they are fairly inexpensive as far as lenses go. You just buy the 16mm and then add on the w/a or FE adapters to it. All 3 fit the Nauticam dome and you don't need a zoom gear. I would agree that the macro lenses are a bit limited, the 30mm hasn't worked out all that well uw, but the w/a is very good.
Panasonic has some very good lenses and shoots excellent video. We have found their cameras to be fussy when when working in optical sync with external strobes. They are also more expensive. But they have more direct controls and better specs in many cases.
Olympus has very easy-to-use cameras and reasonably priced lenses, they are filling in some gaps with new lenses this summer and fall. They seem to work very well in manual and TTL sync with external strobes. Bang for the buck, I really like the E-PM1 and PT-EP06 housing - not the EP06L version whose lights are a joke. The OM-D is making many people sell their big DSLRs and move to a small, high quality camera with great specs and imaging.
But really, I would almost consider the housing before the camera; The
Olympus housings are inexpensive at $599-799ish, as are the cameras -
the PM1 is only $399, but adding ports is expensive. Your best options are the
Zen dome at $499-799, plus the lens. that port may/may not fit a new housing. Although they do seem like they'll fit the new Oly OM-D housings, that may not be true in the future. And they are limited to 135', are plastic and will wear out much sooner and need service or replacement. I doubt there will be much of a resale on them.
If you spend a bit more on a
Nauticam housing, you are buying into a much broader system; many more ports and gear combos, both Pany and Oly lenses fit all the housings. The housings are rated to 2-300' and much more rugged. They can be easily serviced and will last a long time. They usually have a leak detector. They tend to be less bulky, have a much more ergonomic design, better and smoother controls and usually support all camera functions (the Oly's tend not to have the rear dial control). The ports have a locking bayonet mount that is almost impossible to mis-mount. They come in flat, dome and semi-dome designs. They tend to be less expensive as well.
The
Nauticam housing for the OM-D ($1350) is very competitive with the Oly ($995) with all the above advantages. The
Nauticam Pany GX1 is very reasonable at $1200. And you are much more likely to be able to resell it at a decent price, and re-use all the lenses, ports and gears when you upgrade.
Lighting is the most critical thing you will spend money on. Buy more than you need, start with one good strobe and add another. We like the
Sea & Sea YS-D1 a lot - all of us are shooting it now.
So be sure to think through your new system, think though how you want to expand it and upgrade it in the future, and what you want to do with your photos. It may give you a better idea on your present purchase.
Jack