In terms of camera gear you'll probably want a camera with a great full-frame sensor - that means one of the following is your best bet:
Sony A7R ii - A great camera with a killer low light performing sensor, what a lot of the low-light pros are using nowadays. It'll set you back around $3.5k.
Sony A7S ii - Another great offer from Sony in the low-light department - most of what I've seen and used on the older model A7S carried over here with a greater emphasis on filming - this thing is insane at night, the only drawback is the smaller image sizes (roughly 12-17mb files). This camera (body only) will set you back about $3k.
Canon 6D - This is what I'm using now, full-frame sensor, good battery performance, quick, great low-light performance, awesome lens selection, and decent video capabilities. A bit more heavy compared to most mirrorless cameras, but at 1300 for the body and an accessories bundle, a pretty sweet deal overall.
Canon 5D mkiii - Another great low-light camera from Canon - I won't go into details about what this is a good full-frame camera, or why I'd go with this over the Nikon D800, but I will link a video here telling you all the reasons you might consider buying one over the other.