Hey Sashoke, I'm not sure that this is too helpful, but most of the Porcelain-type
Nepenthes ventricosa are from the northern part of Luzon, where the species was first described. Most of the
N. ventricosa in cultivation in the US are from the southern part of Luzon, including the ubiquitous "Red" form. The habitat photo that you posted from Wikipedia is also a southern Luzon plant (from Mt. Mayon). It seems like in a lot of old private collections, there are a couple of pale southern
N. ventricosa plants running around; cuttings come up for sale occasionally. If you know of any
Nepenthes nurseries that sell
N. ventricosa from cuttings, you could probably inquire for some photos of the stock plants and see if it's what you're looking for. My
N. ventricosa, as you know, was a cutting from a botanical garden; it doesn't grow very fast or steadily for me, but I could trade part of it down the line if I figure out how to grow it well.
Here's mine again:
Also, there are several plants around under the label of "Black Peristome" but not all of them are the same. The MT plant seems to be another pale southern Luzon type, but I can't really comment on it because I don't grow it and have only seen juveniles of that clone (it is, however, a known female). Remember that judging a plant based solely on a picture or two doesn't necessarily capture the plant's character. The angle and lighting can often obscure details that you don't notice or simply can't see.
