I think the idea is sound, if much late 1990s (TR3, Alien, Resident Evil, ...)
yet, it sounds like difficult to make.
"hiding out of vision, make no sound" - that's a desirable gameplay mechanic for wich you probably will not find a satisfying ready-to-go add-on, but sth. you'd need to code yourself. IF you can do that, and provide good sounds/soundediting it can be a real thrill, totally captivating, but in my estimation it is sth. for real pros.
anyways, good luck.
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oh, forgot, wanted to comment on this:
Do not worry too much about the story. Characters are much more important anyways imo.
(I've played games with HORRIBLE stories, yet I may like them for gameplay, characters, dialogues, some scenes)
And roughly in the vein of what
MarshmallowCasserole said, less may be more. Like, a really captivating stealth game in particular does not necessarily need much story - athmosphere (and consistent character(s)) are more important.