You should also check out the survival horror RPG Mothership. They're launching a Kickstarter soon for a core rulebook that will have a lot of sci-fi horror setting generation tools similar to Stars Without Number.
Alien: The Blueprints https://www.amazon.com/dp/1785654950/ref=cm_sw_r_apan_glt_fabc_4GDQ446D6M0EY7SQM6X8
I'd go original spooky haunted/monster ship- go Nostromo.
Here is a workable free set of deck plans that work for your purposes-
https://forum.frialigan.se/viewtopic.php?f=99&t=5442
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And if you have time, a tech blueprint book showing ALL the Aliens ships-
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https://www.amazon.com/Alien-Blueprints-Graham-Langridge/dp/1785654950