Tripods:
Buy a carbon fiber tripod. Lightweight , durable offer great load capacity.
I use this tripod
https://www.feisol.net/tripods/travel-tripods/feisol-travel-tripod-ct-3441t-rapid.html Bought this 4 yers ago primarily for backpacking. It is light enough, folds down to compact size yet offers good weight capacity. Good idea to slash a tripod's rated weight capacity by 25-30% especially if shake/vibration free setup is critical.
Other similar brands are
https://www.siruiusa.com/index/photographic/index.html?cid=1
https://benrousa.com/photo/tripods/
Gitzo tripods are very good but very pricey.
Tripod head:
I started out with a cheap Manfrotto ball which I sold very quickly.
Then settled on a Benro
https://benrousa.com/benro-gd3wh-3-way-geared-head/
This one allows 3 axis movements & that capability is useful for making finer adjustments as one is trying to line up camera etc. Great tripod head for both day and night time use. However I personally couldn't get used to the shape and design of this. I was never able to pack it properly on my backpacking trips (which it isn't really made for) so I sold this one.
I use these two for night sky photography:
Excellent quality and design. Made in California. You can get them bit cheaper and no tax on Ebay.
https://www.acratech.net/acratech-panoramic-head-can-be-used-like-a-long-lens-head/
This one allows two axis movement. It goes on my tripod & sky tracker is mounted on this tripod head.
Camera is then mounted on sky tracker using this head. However any decent ball head will do.
https://www.acratech.net/gxp-ball-head/
I use Fornax Lightrack II as a sky tracker. This one doesn't have a in built chargeable battery but in the 'field' I run it using a standard cell phone/tablet rechargeable power bank using 5v to 12v step up cable center postivie pin.
Other options are SkyTracker (pro and basic) & Star Adventurer. These two run on chargeable battery. Can be mounted on photo tripods directly or using what is known as a wedge in astronomy world.
All trackers have pros and cons. I bought mine used for less than what it would cost new.
All my astronomy gear if not new is sourced from these two sites:
Classifieds on astromart.com. This one is $15 per year.
Classifieds on cloudynights.com. Free.
Canon 6d is a great camera for night sky photos because of its excellent signal to noise ratio. Used one can be had for $500-600.
Lens is Canon EF 200mm f/2.8 USM prime lens. They stopped making it but still some available here and there. This lens is an excellent lens for the price even if bought new but most folks overlook it in favor of 70-200mm zoom.
One thing to keep in mind you don't need an expensive lens and expensive camera for night photos. I started off with a cheap 35mm lens bought for $125 on CL.