Possibly irrelevant but I shoot a lot of Milky Way images, currently from a light polluted back yard in Lithgow. I find it's not so much the camera as the lens and focus (and tripod). I have the Rokinon 14mm f2.8ED manual focus I use on my Nikon D810 (full frame) and find focus being my primary issue because of a couple of things, lousy sight and when I go high magnification in live view I seem to get a lot of noise that overrides the stars. I have no idea how to rectify this. Other than taking test images, running the card into the house and slipping it in my computer to view on a 27" monitor instead of the pin sized screen (for my eyes) on the Nikon and adjusting as needed. My son brings his 10" tablet out but that's nowhere near big enough for me to see focus on, I more need a 65" unit..
In saying that I had previously used a friends Canon 5D MK-IV with a genuine Canon 14mm f2-8 lens and the shots were stunning so my issue may be the thickness of my wallet and after market lens I use. I found focus much easier on the Canon but I have had Nikon gear for decades (and a good assortment of lenses for them) and wasn't buying a camera and lenses. I still have the friends original 5D here and an adapter for my Nikon lenses to mount but haven't used it since I lucked into the D810.
The one tip I will give is a good quality heat band for the lens because when the Milky Way is visible it's usually cold weather (locally) or too many mozzies (summer shooting I avoid).
I find stick on velcro spots /strips great for holding power banks/battery packs on tripod legs without my tripping over them in the dark.
As for modified cameras I have seen stunning results from them but at a price, I'm a cheapskate (see broke) who does the best with the equipment I have to play with in a field where the sky really is the limit.
https://i.postimg.cc/tgdG7QQj/Milky-...-3840x5760.jpg
I'm far from an expert in this field, I've done photography for over 50 years, shooting people, faces, places and animals (both professionally and interest) but I just play with this stuff. I'm just as happy standing out under the stars and simply admiring what I consider to be the most beautiful view from earth.
Now you have me wanting to go out to one of a couple of friends with properties out of town and beautiful dark skies where I won't be messing with the local light pollution. I still think I should either take my GOTO mount for longer exposures or build my own light, portable barn tracker, I probably have everything needed laying around plus a new Raspberry Pi 4 (8GB model) I'm sure I could find code to provide accurate tracking for the purpose.
Good luck!
