I have no experience with either, but the Guava paste has a bunch of additives that I'd (personally) rather not use - such as added sugar, citric acid and food coloring. It doesn't look like it has added preservatives, so at least it shouldn't impact fermentation.
Now the Passionfruit Pulp lists "Passionfruit Pulp" as its sole ingredient. I had no idea that this existed up until now, and I want some like yesterday. If it's even remotely good, I will be using it in a mead ASAP, and probably in beer. I might even put it in cider. I love the flavor of passion fruit, but I've never found a convenient source that I would want to use in the brewery until now.
Im trying to find Pulp, I think some gourmet food vendors do offer it frozen, and I would like to attempt either guava or passion fruit for this saison. Some friends in my old Homebrew club were planning on putting Goya Guava puree in a keg filter, I guess to randalize and serve. I was thinking more of putting the guava or passionfruit in fermentation. Not sure if I should add as fermentation ends or do in secondary.