I like your taste in fish!
Any one of them would be nice additions.
But do mind the fish size to be compatible with the angelfish. Angelfish would get big enough to eat P. gertrudae (P. furcatus aka Forktail rainbow is a little bigger, but may also get eaten), Pygmy Spotted Rasboras and Espei rasboras (the taller body Harlequins/Heteromorpha might be safe). Emperors and Threadfins (as long as the females are a decent size) would be safe.
If I had to help rule out some fish, I would not lean toward the pygmy spotted rasboras since they are kind of too small to really see/enjoy, not always as colorful either.
The Forktail rainbows are a little bigger, but not exactly as colorful as P. gertrudae, and they don't have as nice fins to display. Also the Forktails are a bit "too" active, constantly chasing around the females (not so much worried about the females, but the nonstop commotion may stress the other tankmates a bit). Watch some youtube videos too see what I mean to compare their swimming and displaying behavior.
Emporer tetras have nice colors and fins, though in comparison to the other fish, I might say they are a little boring/inactive. Would be good in the 80 gallon though! Take a look at Blue Kerri tetra and Rainbow Emporer tetras also.
Espei's are great fish. Nice color and always active, schooling tightly just like Rummynose tetras. These guys occupy the upper half of the water column.
P. gertrudae are definitely cool. P. paskai/irani are my favorite among the Pseudomugil species. You might also like P. cyanodorsalis, but those should be kept in Brackish water.
Threadfins behave and display their fins just like Psuedomugil species (so do Celebes rainbows). They are larger sized which, makes viewing from afar easier to see/notice. Plus they have more solid color than Pseudomugils.
All nice choices.
Not sure on the 36 gallon dimensions, but personally I don't like to put really active fish like Espei's in anything smaller than a 40 gallon breeder.