My favourite Lovecraft stories are "The Colour Out of Space" and "Rats in the Walls", but I have a hard time imagining the former as a movie - the specific idea of an unknown colour is part of the story's charm (and I feel it'd need to be padded out to film length, which is why Lovecraft's longer work is better suited).
I also imagine Giger must be a Lovecraft fan
Giger had an artbook called the Necromonicon... so... yes.
and Del Toro has said that he was concerned that a post-Prometheus Mountains movie would feel too similar to the Scott film.
was effectively scrapped a while before Prometheus
, so it's quite an academic comparison. And Mountains - with its wintry Arctic secret city inspired (as Lovecraft repeatedly reminds us) by a Nicholas Roerich painting and elaborate history of the various terrible Old Ones - is sufficiently different and more narratively satisfying.