As far as Krypton locations go, in Superman:Birthright the Andromeda Galaxy was stated as Krypton's location.
It has also been mentioned to be in the Milky Way and in a sector of space close to Earth, 50 light years away. Tomar-Re was also supposed to be the Green Lantern assigned to the Krypton section.
And it's been many years since I've seen the Donner movies but didn't they say little Kal's ship would travel through six galaxies to get to Earth? I guess that could mean it's either beyond Andromeda or even in one of the dwarf galaxies orbiting the Milky Way.