A few of the dvd and bluray cover sites will likely have the official covers - and few similar custom-made ones too 😃
Sites like http://www.customaniacs.org/forum/ & http://www.hirescovers.net/forum/index.php & http://r1db.com/covers/ & http://forum.blu-ray.com/showthread.php?t=100007 & https://www.freedvdcover.com/blu-ray-dvd/ etc
The 2 main threads on here to feature covers are:-
the dvd covers thread - http://originaltrilogy.com/topic/Star-Wars-DVD-Covers/id/741/page/181
Blu-Ray and other HD box size STAR WARS covers - http://originaltrilogy.com/topic/Blu-Ray-and-other-HD-box-size-STAR-WARS-covers/id/11843
though there are many more great threads to feature some quality covers on here too - it’s really a question of sifting through the various threads to find what you like…
It may also be worth typing into google images and other search engines ‘star wars custom blu ray covers’ for some similar or slightly amended covers too.
Good luck with it 😃