Gobae

This is what I purchased to shoot tethered for my D7200. Assuming the gimble uses a standard usb 2 port on it's end something like this is probably what you're after. https://www.amazon.c...duct/B01FG7UB0U

Since the D7200 follows the SDXC standard, 2 TB is the max SD card capacity it can handle.

I've got a D7200 and thought you could customize the "i" (info) screen. But after looking in the original camera manual as well as in "Mastering the D7200" (which is better than the manual IMO) I was unable to find anything.

I was really kind of hoping to find what you're talking about, because the D90 had that info on the top LCD and I kind of miss it. But no luck

My upgrade path was very similar to Morticia's Keeper.

I started with a D40X -> D90 -> D7200. I still use my D90 as a second body and would totally recommend it as a D40 upgrade. For me the biggest advantages (over my D40X) were the additional focus points, frames per second, higher ISO and internal focus motor so I could seamlessly use legacy glass from my wife's N6006 film camera.

That said, make a list of where you've outgrown your D40. You may find a newer generation D3XXX, D5XXX, D7XXX would be better than a D90 since that camera was discontinued in 2011.

16-35mm is a good wide angle for astro, photography. But if you can get it in the 2.8 version that'd be even better for astro shots. With a bigger aperture your shutter speed can be faster reducing the amount of star streaking and the amount of time the sensor will be on continuously (thus running cooler and less "hot spots" in the photo).