1176 or la2a style comp (depending on the vocal) works wonders - the antress modern stuff is pretty cool. i'm sure the UAD stuff is excellent too. soooo different to just compressing with a "regular" compressor like blockfish, classic compressor etc.
delays, the classic delay is ok, and free. i haven't found a better one yet, in the freeware realm at least.
ferox saturation is also cool, but really depends on the source.
for reverb, freeverb 2 is excellent. also great for drums.
with those ambience effects it's really important to eq them to fit in the mix better.
but if i had to name one thing that's absolutely essential for *that* vocal sound, it would be the compression. you can use basically anything that's not total shite for ambience, but trying to get the compression right with slower attack comps is an uphill battle imho.