Here are some good products for night sky photography:
The Nikon D750 is one of the best cameras for night sky photography with low noise levels and the usual Nikon ruggedness.
The Canon 6d has been around for a while but it is a very good option for Canon shooters.
The Sony A7s offers impressive night sky capabilities, including video at very high iso.
The new Sony A9 promises even better night sky capabilities.