Actually, you have the additional choice spending less money by opting for a different housing for your D7200 rather than a Nauticam.
I shoot a D7100 in an Ikelite housing and do very well without an additional viewfinder (again, less money). I also do well with an Ikelite 8" dome port and a mini-dome port. The 8" dome works well with my Tokina (on those rare occasions that I use it) and my Nikkor 16-85mm. The mini-dome is designed for my Nikkor 10-24mm (most used lens in my underwater system). I find the usefulness of the Tokina limited unless I'm shooting large animals like manta rays.
You might want to consider purchasing an Ikelite housing and use the money you save to add some lenses and ports to your D7200 system. Feel free to checkout my website portfolio at firstname.lastname@example.org.
I plan to send my D7100 Ikelite housing in to have the strobe electronic package upgraded to use with both my D7100 and D7200 bodies.
My response to your post is not intended as any kind of 'dig' against Nauticam housings. I have several friends who use Nauticam housings for their Nikon and Canon cameras. Nauticam makes a great housing and I'd probably have one if my budget had been bigger when I initially invested in my system. Despite its clunky looks, the Ikelite has been a great housing for use with my D7100. I also have a vintage Ikelite housing for my N8008s film camera (it stills works very well).