Here is a script that installs the full imaging stack, based on Ubuntu 20.04 32 bit:
github.com/avarakin/AstroPiMaker4
Installs most commonly used Astrophotography software: INDI , Kstars, PHD2, CCDCiel, Skychart, Astrometry with sextractor, ASTAP plate solver
Sets up Wireless Access Point
Sets up x11vnc to be started automatically
Configures screen to be 1920x1080 for headless operation
Defaults to KDE Desktop, but Gnome and Mate can also be installed
Miscellaneous software:
Syncthing for syncing images into processing PC
Arduino IDE
Latest Libraw with Canon CR3 support. At this point, only CCDCiel is working with this library, Ekos crashes with it
Full headless operation
I don't think all software is available for 64 bit yet and I think 64 bit is an overkill. I run everything on 2G Pi4 without issues.