How about a Canon GX9 and Fantasea housing? You can get both new for under $1000. Adding a strobe, tray, cable, etc would be your path for upgrading first. You can add wet lenses for better macro and wide angle later if desired but you can have some degree of macro and wide angle with the camera as is. If you stretch a bit, maybe you get to a used strobe now. The GX9 Mark II is out so the GX9 price is dropping.
The GX9 Mark II and housing are also at your $1000 budget but then there is nothing left to plan for lighting.
If you are patient, you might find people selling their GX9 to upgrade but that will be less certain on timing.
Capt Chad, you will have no trouble with a standard tokina 10-17 lens with the D7000, which I use as well. The D7000 is a DX camera and the lens is designed for such a camera. You can also use domes in the 4 inch sizing with that setup. There are several mfg companies with small domes for that lens and camera setup. Its quite compact for travel and very nice for close focus wide angle. The lens will focus all the way down to the dome.